Nature Watch, Cable Natural History Museum

The Nature of Seeing

2011-06-29T11:47:00.000-07:00

Nature Watch
The Nature of Seeing
By Susan Thurn,
Cable Natural History Museum
For four years now I have written this Nature Watch column every week. I have written about what to watch for in nature. I have received thousands of comments and heard stories from readers about their own observations in our north woods natural world. We are all phenologists, those who study the seasonal changes in nature, and we primarily do this through sight. We notice a movement out of the corner of our eye and suddenly see our first pileated woodpecker. A flash across the road comes in front of us and we have just spotted a timber wolf. It is our sight, an amazing sense, which provides such an important skill for discovering what surrounds us.

Our eyes contain many essential parts, but two of the most interesting to me include rods and cones. Inside our retina, a part of our eye the size of our thumbnail, are about 150 million light-sensitive rods and cones. Rods help us identify shapes using light. Cones identify color. Both cells then send information to the brain (believe it or not, the image sent to the brain is upside down, and then our brain turns the image right side up and interprets what we are looking at.) These are amazing details and operations that occur, but let us take a look at some specific animals and their visual adaptations.

An owl, if it could read, could read a newspaper from the other end of a football field. This makes sense since their eyes are one-third the size of their heads. They can see a mouse moving over 150 feet away with light equal to that of a candle. They can follow their prey with a head that can turn 270 degrees in each direction. Their relative, golden eagles, can see a rabbit from two miles away. This is astonishing eyesight!

Other daytime birds can see greater ranges of colors, including ultraviolet light. Pigeons have more cones than humans, so can see millions of different hues and are thought to be perhaps the best on our planet at detecting color.

Most snakes have two ways of seeing. Their eyes detect color quite well, but they also have a deep pocket called a pit organ that detects their prey in infrared. Chameleon's eyes can look in different directions at the same time. Frogs must pull their eyeballs in their body to blink. In the fish world, a flounder has both eyes on the same side of their body, allowing them to lie flat on the floor with both eyes looking upward.

Insects are famous for their compound eyes with many tiny parts. Some insects have up to 30,000 lenses in each eye in a honeycomb pattern. Each lens then makes up a small part of the overall picture like a jigsaw puzzle. This vision helps them in detecting movement, which comes clear to us as we try to swat a fly or mosquito! A dragonfly’s brain works so quickly that most movement they see appears to them in slow motion.

Some insects see color, although not as clearly. Butterflies can see colors better than humans while others cannot see as many. Bees see blue, green, and ultraviolet colors but do not see red.

Crab and shrimp are animals with some of the least developed vision. They have compound vision like insects, but with far less detail. Instead, they are very skilled at detecting movements, a behavior that helps them avoid predators.

Perhaps the next time we see the night-time flash of a nocturnal animal’s eyes, we’ll better appreciate how animals see the world. It amazes me that such amazing visual abilities exist in animals, and this is an exploration of only one of their senses!

The place in which we live brings continual wonder. It is this variety that adds to our days, and has added to the many articles in which I have enjoyed sharing throughout the past few years. This issue will be the last Nature Watch written by my hand. It has been great fun writing and learning with you, and I have loved every minute of it! Readers will now be able to enjoy the energy of new Museum staff who will share the wonders of the natural world. However, if you see me on out on the trail, or on the street, I hope you’ll continue to share the stories of your own adventures in our incredible north woods.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Tick,Tick,Tick

2011-06-16T10:19:00.000-07:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

I went walking through a grassy field today and afterward felt like I was covered in ticks. Every single one of them was a wood tick, which I would prefer to a deer tick any day. A few moments later, the ticks were nothing compared to the mosquitoes. Still, wood ticks are a part of our northwoods life. We walk through our yards and find them on our pants afterward. We dedicate moments at events to tick races. We have wood tick festivals that include music, cook-offs and other events dedicated to fun in the northwoods in spite of the ticks.

Many people think that ticks are insects, but with their eight legs they actually belong to the spider/arachnid family. All ticks begin life as an egg, and after hatching, the larva is called a seed tick, and it feeds on a small mouse or bird. The larval tick then develops into a larger nymph. This tick then feeds on a host and molts into an even larger adult. Finally, male and female adults feed on a host such as raccoons, dogs, or other large mammals, and the males often look for the female while on the host. Then the females lay up to 5,000 eggs after their last feeding.

When latching on to their host with their two-part mouth, they use saliva to create a cement-like connection. They use their mouthpart to cut a hole in the epidermis, or top layer of skin. Ticks excrete an anticoagulant to keep the blood from clotting. They have adapted quite well to feed on their hosts!

For the many who believe that ticks jump from trees, this is actually a myth. Ticks actually wait for their host animals from the tips of taller grasses and shrubs. With eight legs, they use the back two legs to hold on to a piece of grass. The front six legs are then used as seekers to continue sensing their next “dinner.” Ticks sense heat and carbon dioxide from their host, so when brushed by a moving animal or person, they quickly let go of the vegetation and climb onto the host. Ticks can only crawl, not fly or jump. Any ticks that have been found on our scalps crawled there from our lower body parts. Some species of ticks will crawl several feet toward a host. A study in northern California states that if a human sits on a log for five minutes, they have a 30% chance of having a tick crawl on to their body. Although most spiders and insects are not active until the temperatures reach about 60 degrees Fahrenheit, ticks can be active at a much cooler 45 degrees.

The best method to remove a tick is to try to use tweezers to flip the tick’s body so that it is almost upside down, and then pull straight up to try and remove the tick. Doctors recommend great caution in trying NOT to squeeze the tick, as any diseases that may exist in the tick can actually be squeezed back into our bodies. The best prevention is to regularly check our bodies for ticks, and when outdoors, put our socks up over our pant legs, and wear lighter-colored clothing (it is believed that darker colors more closely resemble that of darker-furred animals so common in our northwoods environment.)

For over 43 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Fledglings

2011-06-09T08:04:00.000-07:00

By Susan Thurn,
Cable Natural History Museum

It is not an action we see in the natural world very often. It happens in tremendous numbers every spring, yet we humans rarely get a glimpse at it. Sometimes it is a simple plop, plop, plop, as the fledgling wood ducks drop from their wood cavity or wood duck house into the water or a swoop as a bird leaves its nest. The process of birds leaving their nest is so common, yet not often seen. Why is that?

Many bird nests are very difficult to find, hidden nicely among the camouflaged plants. Young fledglings are also expert ventriloquists, something that helps them evade predators. Their sounds are usually short notes that become faster whenever an adult brings food.

A baby bird is sometimes called a fledgling, the stage in which the young bird’s life has wing muscles and feathers that are developed enough for flight. It is also considered the time when parents of a chick raise it to a fully grown state. Sometimes the birds have begun flying, but are still dependent upon care and feeding from their parents. Other times birds are “fledged” once they leave the nest, even if they still haven’t flown.

Contrary to what we might think, songbirds don't "learn" to fly, and their parents don't "teach" them. Young birds have innate abilities to fly as their bodies mature gradually. When they are physically ready for flight they will fly.

It is common during June for humans to see immature birds sitting on the ground or hopping around without sign of their parents. This is a normal occurrence, as the parents are probably either hiding, watching quietly nearby or are not far away collecting food.

How can we know when we see fledglings? They are usually clumsier and less active than adults, and may have lingering tufts of down feathers and a shorter tail. They will sometimes sit in place, fluttering their wings and gaping their beaks when adults bring food. Most songbirds have a brightly-colored inner beak to help parents find their mouths, but this feature is lost as they age. As they mature, many fledglings will follow their parents, begging constantly for food.

Young of open-nesting songbirds often leave their nests within fourteen days. However, the cavity-nesting tree swallow stays in its nest longer, up to 19 days if the weather conditions and food availability are good. More young in the nest also can take longer for them to mature. With tree swallows, only 85% of their feathers are fully grown when they fledge and attempt to fly.

Pigeons stay in their nests until they are almost adults. The nests are also well-hidden, so are difficult to find, as is true of so many birds. Pigeons sometimes become even bigger than their parents as they feed and get ready to be out of the nest on their own.

Robin nestlings are fed at first by regurgitated food, then larvae or whole earthworms. After they fledge and leave the nest, the young are fed by the male for at least two more weeks. This assistance from the male allows the female to begin another clutch of eggs.

There are many more interesting stories about birds and their parental care of young. Birders are beginning to gain more interest in observing the fledgling process, recording the young birds’ calls and learning identification techniques. If you have your own stories to share about observations of birds fledging in your own back yard, be sure to share it at the Nature Watch blogspot address listed below.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Barren Strawberries

2011-06-02T13:30:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

When we walk through the forest right now we see the beautiful white of the trilliums, the white of the spring beauties, hepatica, bloodroot, starflowers, spring anemones, the multi-colors of the wild violets, and one of my favorites, the yellow barren strawberries.

Barren strawberries are common in woods and clearings, rising up out of the ground from 3-8 inches. The yellow flowers have five petals that bloom into June. A flower that belongs to the rose family, its leaves are made up of three leaflets on long stalks that are oval-shaped, with broad teeth. The fruits are not really berries, but have single seeds that are inedible, which is where the name barren strawberry comes from. It also grows close to wild strawberries.

Easily grown in well-drained soil in full sun to part shade, barren strawberry spreads across the ground with runners, or rhizomes that creep just below the surface of the soil. They can grow in many soil types, but actually prefer slightly acidic soils. Due to its adaptability, this plant can be found in a variety of habitats such as meadows, deciduous or mixed-hardwood forests. Plants often seen growing along with barren strawberries include sugar maple, white ash, ostrich or cinnamon fern, and false solomon’s seal.

Barren strawberries are considered an endangered species or plant of special concern in some states. Garlic mustard and other invasive plant species have pushed out this plant in many habitats. In other areas barren strawberries are used as native plant ground cover for difficult areas around our homes. It has even been used in xeriscape gardens because it is drought tolerant.

Spring brings so many amazing things to observe every day. Be sure to get outdoors in our northwoods back yards to enjoy it all!

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Bloodroot

2011-05-25T13:34:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

I saw it from across the yard. A small, white flower that I know wasn’t flowering there last spring. I stopped mowing my yard several years ago, and all of the native grasses and plants have moved in, keeping a different kind of landscaped space, one that is still a low-growing lawn only a few inches tall, and a lot more interesting. I never know what is going to pop up next. I have explored it all, and know where my barren strawberry, trillium, bunchberry, and hepatica are located. This, however, was a most exciting discovery in my own back yard – a bloodroot plant.

How did this bloodroot come into my yard from nowhere? Perhaps I can thank the ants. Bloodroot has a part called an elaiosome that attracts ants. The ants bring the seeds to their nests, where they eat the elaiosomes. They then leave the seeds in their underground waste storage areas, where the seeds are stored until they can germinate in a bed of nutrient rich ant waste.

Bloodroots have up to twelve delicate petals with a striking inner yellow color. The flower blooms before the leaves unfold. The one plant in my yard could likely become a large colony over many years.

The bloodroot plant has a very interesting folklore history. Bloodroot is named for its orange colored rhizome growing under the surface of the soil. It was used by Native Americans as a dye and herbal remedy made from the red-colored sap. It has been used to promote healthy marriages and families. It has also been used as an anti-plaque or anti-bacterial substance in toothpaste and mouthwashes, but can actually destroy skin tissues.

The smile on my face upon finding this bloodroot plant was a mile wide. We sometimes feel a special connection to a family member, our pets, or a special animal. For me, today I had a special closeness to a bloodroot plant, in my own back yard. It is just one of spring’s delights we can enjoy in our north woods.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Green

2011-05-17T11:52:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Green. Verde. The color of spring. After the last rains, I looked around outdoors, and the color green is everywhere. It is beautiful, in the grass, in the trees. The word itself resembles the old English verb “growan” which means “to grow.” We are definitely seeing the color green and growth in nature in the north woods.

The color green is often seen in nature due to chlorophyll, the chemical known to assist plants with photosynthesis. Chlorophyll absorbs sunlight wavelengths of most colors, but reflects green light.

Many animals such as amphibians, reptiles, birds, insects or fish, use the color of green as camouflage to blend in with chlorophyll green colors. Again, these animals appear green because of reflected light. Some insects or other invertebrates have pigments, sometimes caused by their diet, that give them a green color. Beetles, caterpillars, spiders, and flies incorporate green pigments into their exoskeletons. A species of sea slug is green because it ingests algae, and it transfers the chloroplast cells from its food into its skin, which then allows it to take the sun’s energy just as plants do. The two-toed or three-toed sloth is so slow that blue-green algae grows in and on their fur, hiding them from their predators, the harpy eagles. Green Turtles get their name from a layer of green colored fat that separates their inner shell from their internal organs. There are many other chemicals and pigments that contribute to green coloring in organisms, even including our very own green pigment in our stomach bile.

It might not be easy being green for Kermit the frog, but it is certainly a common color in so much of the natural world. I have longed for a better green thumb for most of my adult life. Some believe that the grass is greener on the other side. Many of us are going green, taking action to help protect the environment. Whatever it may be, the color green is a welcome to us in spring.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Living in a tree house

2011-05-11T07:42:00.000-07:00

Nature Watch,

By Susan Thurn,
Cable Natural History Museum

I live in a tree. It is a cedar tree, in fact. I woke up a few nights ago in the middle of my night’s sleep to a scratching noise. After further inspection, I noticed a sound coming from the outer bark of our comfy treehouse. I popped my head out of the main cavity, and was surprised to see a flying squirrel scurrying away. I looked at the side of the tree, and the flying squirrel had been chewing right on our bark!

This treehouse of ours is a bit more square than others. It is, of course, our house rather than a living tree. Imagine my consternation to discover a flying squirrel was chewing away at its cedar exterior. Was it trying to create a nesting cavity in our house?

It turns out that North American flying squirrels use many different types of nests. They have day-time sites to den in which scientists call refugia nests. Their natal nests are used to raise young. During the winter months they live together in aggregate nests, in which large numbers of family and non-family members reside.

The materials flying squirrels use in these nests depend upon what is available. However, in a study done in Canada, almost all of the flying squirrel nests found had strips of white cedar bark within them. Flying squirrels also use moss, lichens, animal fur, bird feathers, leaves and twigs, or even human-made materials such as newspaper or insulation.

The cedar that built our square, A-frame house does not just make good housing materials. Flying squirrels apparently have discovered that there are other benefits of having cedar in their nests. The white cedar bark and wood has insecticidal and water repellent oils.

There are just a few more things worth saying about flying squirrels. Not true fliers, they actually glide using a fold of skin that goes from their front wrist to their hind ankle. They glide up to 120 feet, able to change speed and direction just with movement of their arms and legs. Their fluffy squirrel tail stabilizes them in flight.

Flying squirrels forage for food at night with their keen sense of smell. They will eat plant seeds, leaves, nuts, sap, bulbs, roots, flowers, or bark. More specifically, they will eat mountain ash, juneberry, pin cherry, hazelnut, balsam, and maple seeds. They also will eat fungi or bird eggs, worms, or other small animals. During late winter they will even eat the buds of trees as food becomes scarce.

The siding of our “treehouse” looks a little funny now, with chew marks and scratches in several places, but nothing a little stain wouldn’t hide. Although I am happy that perhaps this flying squirrel isn’t trying to chew a cavity through our house, I also feel lucky to live in the north woods. Flying squirrels are just another animal species to enjoy in our own back yards.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds: Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Phoebes

2011-05-04T09:09:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Here is a question that came from a good Museum friend with whom I always swap nature stories: “I know we both had phoebe nests that had activity the past 2 years. The first year the couple had one set of eggs; the second summer they had 2 sets of eggs. Although I hear them back in the yard, I haven't seen any activity in the second year nest. I was wondering if you were seeing them back and not using their nest?”

Phoebes and humans often share the same house. Every year our Eastern phoebe finds a sheltered spot under the eaves of our house to make her nest, although some birds of this species will consider a porch, windowsills, porch rafters, or even inside a barn. The female builds her nest over several days. Six inches square is about all she needs to build upon, and moss and mud seems to be two of her most common nest-building materials. They also will use mud, lining the inside with grasses, hair, and feathers.

Phoebes are quite loyal to their nests and will often build right on top of the previous year’s nest. They can reuse them for several years, as a little spring cleaning makes an old nest look like new. Under one bridge in New England, generations of phoebes were known to return to breed for over 30 years. At my own house, I have two different nest sites that have been used two different years, but then the nests were abandoned for other places around my house, always under the roof eaves.

She doesn’t like it when I get near her nest, but each year I check in on the phoebe’s young to make sure they’re doing well. I have learned from bird guides that phoebes are more tolerant to humans, but I avoid looking at the nest right before dusk, as the adults may not see well due to the amount of daylight, and not return to their nests. My actions then can end up doing harm to the young birds.

Phoebes are common cowbird hosts, a bird that lays its eggs in other birds’ nests. The young then push out the young to be raised by the adoptive parents. To combat this parasitic bird species, phoebes sometimes will build a new nest floor right over the top of the cowbird eggs.

The Eastern phoebe is a delight to have around in our back yards. They are valuable to us as they consume many pest insects that are also making their homes in our back yards. Their song begins early, and is beautiful to hear. Phoebes typically land on the same roost, and are fun to watch as they repeatedly twitch their tails. They are also fund to watch, as they are active flycatchers, swooping from trees in almost circus-like antics as they move to catch their insect food.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds, Feathers in Focus opens in May, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Spring Peepers

2011-04-28T08:40:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Little Frog with a Big Voice

“Peep, peep, peep,” is the incessant voice of a little frog with a very big voice. It is a sound I look forward to every spring. The spring peeper is light brown in color with a darker cross that forms an X on its back. With a length of one to one and half inches long, and a weight that is only that of about a penny, they are amazing amphibians. The peeping sound they make in the spring is worth a trip outdoors on any warmer night.

Spring Peepers are first heard in March or April, once the ground is thawed enough by early spring rains, or as snowmelt fills lowlands, ponds and wetlands. These vernal, spring-time ponds and other wetlands are the host to these peepers that spend other parts of the year in forests near their permanent or semi-permanent wetlands. Woodland ponds that are filled with shrubs, branches and twigs above and in the water are preferred areas as well, where they can grasp on branches or cling to the edges.

It is only the male peepers that have a vocal sac near its throat that expands and deflates like a balloon to create the distinct peeping sound. They use the sound to attract the ladies. Male spring peepers call out from their perches in the brush or on grass edges, above the water to attract female attention. When we come close, they hop in for safety.

Dusk and early morning hours are preferred times for spring peeping. Their calls can be heard from up to two and one half miles away depending on the amount of peepers in the pond. One small pond typically has hundreds of individuals all in one place, making a very loud sound!

When eggs are laid, one spring peeper female can lay up to 1,000 eggs which are hidden at the water’s base near vegetation. For the next 8 weeks the young feed on algae or other organisms in the water as they go through the larval tadpole stage.
Spring peepers are active nocturnally, where they feed on invertebrates like worms, spiders, and insects such as flies, beetles, or ants. Although they are considered a treefrog and have toe pads to allow them to grasp on to trees, they usually do not climb higher than our knees.

Because they are cold-blooded, spring peepers go through a form of hibernation. Parts of their bodies will freeze and have ice crystals in them. However, spring peepers can produce glucose in their livers, a sugar that acts like anti-freeze. This glucose is pumped to their heart and lungs so they can survive even sub-zero temperatures.

When is the best time for one of those evening peeper strolls? Spring peepers will call down to a temperature of about 36 degrees Fahrenheit, so almost any night is a good night to enjoy these great amphibians in our back yards!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, The Joy of Birds, Feathers in Focus opens May 3rd, 2011. Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Every Moment Matters

2011-04-20T09:00:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Saturday brought my first Eastern phoebe, the first sound I heard when I awoke. Sunday I experienced my first deer tick. Monday I saw two sandhill cranes fly overhead. Tuesday I saw a wolf and my first butterfly of the season, a Compton’s tortoiseshell. Wednesday my husband saw his first bear of the season and I tasted the first spring’s maple sap from a friend’s maple sugar bush. Thursday a northern flicker flew away from the roadside as I drove home. Friday a turkey vulture flew overhead, looking as if it was sauntering north to wherever it calls it’s second home.

Today in school we went outdoors to watch and listen. Red-winged blackbirds were singing everywhere as they are migrating through. Large flocks of slate-colored juncos were swarming through in their migration. Grackles were flying from tree to tree.

Others excited by spring’s changes have told me of their observations as well. Trumpeter swans are migrating through our area. Loons are back on many of our area lakes. Water birds like northern shovelers, American coots, mallard, redhead, and wood ducks can all be observed on bodies of water. Chipmunks are out of hibernation. Song sparrows, kingfishers, kestrels, and tree swallows are all returning.

I have tasted the sweetness of spring, smelled the earth’s soils, stood in the year’s first rains with raindrops coating my face, and listened to the music of the frogs and birds. Every new observation, even for the forty-second time, (give or take a couple of years,) is a wonder each and every time. I am a phenologist, someone who joins many others every season in watching nature’s changes.

Every Act Matters. This is one of the themes for this year’s Earth Day, which takes place every year on April 22. Become a phenologist. Get outdoors on Earth Day and every day, and see what can be observed in our new spring. Enjoy what is in our north woods back yard. Care and protect everything we can. Every act, every moment matters!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Gray Jay

2011-04-08T07:32:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Friends of mine who are members of the Museum, suggested that the Canada, or gray jay was worth writing about, and after researching them more, I have to agree. Gray jays are residents of northern Wisconsin, but tend to be more common in more remote areas. They prefer habitats that include black or white spruce, or jack pine. It is believed that cold temperatures are a key requirement of habitat to ensure that these birds will survive.

Gray jays have an amazing adaptation, the ability to use glands in their beak to secrete a mucous, or sticky saliva. Using their saliva they glue together groups of berries or other perishable food and wedge it into the bark of trees. The bird is preferential to certain tree species simply because the bark is designed with scales that hold the food better. The colder temperatures mixed with antibacterial properties of the trees work to keep the food from spoiling. The jays will cache thousands of food objects during the summer for their winter use.

During the warm months, gray jays eat beetles, wasps, caterpillars, grasshoppers, or other insects or arthropods. They also eat small rodents, nestling birds, eggs, berries and fruit. They have even been observed eating fungi and slime molds. Sometimes they will eat their prey live. Gray jays also have been observed feeding on engorged ticks off of moose.

Gray jays are often called camp robbers because of their behavior of stealing human food. They will enter tents or camp buildings in order to steal food. They then leave quickly to eat or store their food some place else.

Another interesting feature about the gray or Canada jay is that they begin nesting much earlier than other birds, right now in March and April. Scientists believe that nesting now might provide an advantage for the adults while they still have winter food cached to feed their young.

However, what happens after they leave the nest is a surprise. At first, the siblings huddle together to share their warmth, but five weeks out of their nest they begin to fight, and the dominant youth will push the siblings out of their territory. The “boss” juvenile will then stay with their parents through the next winter, learning, being protected, and benefiting from adult food supplies. The “brothers” and “sisters” then experience a mortality rate of 80%, most of them dying by fall.

Get outdoors and listen for the soft, harsh, "cha-cha-cha-cah” calls, or the whistled “whee-oo.” Look for the large gray songbird with a long tail, pale gray face and forehead, and a dark cap that extends down onto its cheek. Maybe you will be fortunate enough to see one in your own back yard!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Or find us on the web at www.cablemuseum.org, discover us on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Bald Eagle

2011-03-30T10:20:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

They have a seven-foot wingspan. They can fly average speeds of 30 miles per hour. They are amazing predators in the sky. They are incredibly beautiful. They are America’s symbol. They are the bald eagle, and they are something that most humans never tire of observing.

Saturday evening I was at a Cable community event, and several people asked if I’d seen the eagles near the Namekagon River on County Highway M. My family and I saw four of them, although others shared that they had seen ten earlier in the day. The excitement was shared by all of the observers.

Research has shown that bald eagles in the Great Lakes area don’t usually migrate. Our northern eagles fly far enough south to find open water with sufficient food supply. An eagle can travel up to 100 miles on a winter day to find food.

The week of March 22, 2011 brought a huge number of migrating eagles back along the Mississippi River, a place not too far away from us as the “crow” flies. The bald eagle can fly hundreds of miles in just a few days. They migrate in large groups, streaming along in a path that can be up to thirty miles long with over a half-mile width. Daylight is the cue to migrate rather than weather, so eagles can migrate north to their home range to find that winter is still present. Then they cope with food availability, often depending on road kill for their meals if open water is not an option.

Bubbles of rising, warmed air, called thermals, are what aids eagles in migration. They glide on these thermals in the desired direction until they find another. This method of flight allows them to conserve energy.

Eagles are diurnal (daytime) fliers, and probably use landmarks to guide them to a home territory, while using more specific cues to find their nest tree. Clearly their memories must be great, showing a high level of intelligence.

Immature bald eagles will often wander back to their birth territory in the spring, but do not always stay put. Usually around age five, when they reach sexual maturity, they will establish nesting sites within 300 miles of their birthplace.

Living among some of the greatest bald eagle habitat, we are fortunate to be able to see bald eagles almost daily. They are an integral part of our ecosystem, one that is worth taking great care of, here in our own back yards.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Spring Music

2011-03-24T09:58:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

I couldn’t stop smiling this morning. I heard the familiar sound of a honk as I left my house for teaching today. I looked out across the field, and saw a Canada goose flying by the house. Its honk called to me, reminding me of migration and warm weather and spring!

Here are some fascinating facts of a very versatile bird:

The further north we live, the smaller the geese are. There are eleven subspecies of geese. One of the subspecies is named the cackling goose, and lives in the very northern parts of Canada.

Canada geese tend to choose a mate of a similar size. This is called assortative mating, which may help ensure better reproductive success. Pairs mate for life and remain together year long. During most of the year the geese stay together in large flocks that are often related to each other.

Every spring when the geese land in the field, I watch them circle, and then a small group peels off before landing. Around goes the remainder of the group in flight, while another group alights. When Canada geese migrate, they stay in these family groups, and it is these same family groups that land each time.

During our spring, geese feed mostly on grass and sedges, which allows them to do well in a variety of habitats. They also eat a more elusive plant, the skunk cabbage. Geese have become more successful due to agricultural practices, feeding on grains, as they are very adept at removing corn kernels from the cobs. Fall and winter is a time when they rely more on seeds, berries and grain. Their ability to eat crops and grass has opened up both rural and urban environments, decreasing their migratory habits and allowing them to stay in many areas year round.

When a flock of Canada geese get ready to take off in flight, they join together in the chorus of loud honks in which we are all so familiar. Geese also have loud calls when threatened or excited. In addition to their calls, geese apparently have a host of body moves that are worth observing when one gets a chance.

Spring has sprung. Take time out to enjoy the outdoors, listening to the easily identified honking as it spills down from the skies. Look for the “V” of migrating geese along the horizon. Acknowledge the hallmark of a new cycle of life. Enjoy these pleasures in our own north woods back yards.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com to learn more about our exhibits.

Spring has Sprung

2011-03-16T07:04:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

I had a headache today. It burned and made teaching fourth graders much more difficult. The headache wasn’t from the teaching, however. Nor was it from a cold that's been pestering me. It was a change in the weather that made it that way, a change in the barometer that makes my sinuses go mad. It was a sign of spring on its way that lifted my spirits in spite of the pain.

We are approaching the spring equinox, March 21, labeled one of the great solar celebrations of the year. It is the time in which day and night are nearly equal, and about to tip over to the light. Daylight will continue to lengthen, and is also just one of the precursors that spring is on its way. There are many other things in nature that will be happening now and in the next few weeks in which we can look for.

Right now, according to mom’s report from the feeder, the American goldfinch is returning to its bright, brilliant colors. As they lose their feathers, or molt, the goldfinch gains the yellow plumage in the male. The color is produced by carotenoid pigments such as beta-carotene that come from their spring plant diet, important when they are replacing their contour, colorful feathers.

Tree sap will begin to flow as our days get warmer. The sugar maples will become a source of future delight that we can taste from its syrup.
Chickadees also begin their spring mating call, which sounds more like a “fee-bee” sound than the typical “chick-a-dee-dee-dee” song we are used to hearing throughout the rest of the year.

Ruffed grouse begin their drumming that will continue into May. Male grouse begin declaring their “property rights,” or territory, by beating their wings against the air to make a thunderous drumming sound. The drummers stand on a log or mound as they beat their wings to protect their home range up to ten acres.

Large mixed flocks with male red-winged blackbirds will soon be migrating back. We’ll most likely hear them in trees or wetlands as they chatter with one of the first spring bird songs.

Woodcock also return for their spring courtship display that the male uses to attract females. The males begin their song and dance at sunset, in a field or clearing. He sings out, calling repeated “peents,” followed by an occasional bobbing of his head, a turn, and a repeat of the dance again while broadcasting his song in different directions. They then fly upward into the sky in a wide spiral, moving higher and higher. As he gets higher, the male’s wings whistle, creating a “twittering” sound. Finally they begin their descent downward, zig-zagging back and forth, down to the ground without a sound.

If spring fever has any of us in its grip, it is time to get outdoors! Walk, whether down the road or in your own forested back yard. There are many exciting signs that spring is on its way for us to see and enjoy!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Weasels

2011-03-10T08:10:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Our neighbor asked about weasels because he has seen one running around in his yard. Wisconsin is home to three species of weasels – the long-tailed, short-tailed, and least weasels. They are 8-16 inches long, and with the exception of the least weasel, have black-tipped tails in the winter. The last time I saw a weasel I’m pretty sure it was a long-tailed weasel, about 16 inches long. Two of them were chasing each other around in the middle and side of the road, and so I stayed put in my car for quite some time, just watching their antics.

White in the winter, except for the white tail, long-tailed weasels are thought to be more nocturnal. They are active all winter long, and some evidence suggests that they may be more active during the day in the summer. They shed their fur twice a year in our climate from brown to white, while in a southern climate stay brown all year round. They live in unused burrows, uprooted tree roots, under rocks, or in rotting logs. They can be found in almost any habitat, but preferably one near water, as they drink a significant amount of water each day. Their home range can be up to 40 acres of land. Although a male’s home range may overlap many female home ranges, home ranges of adults of the same sex do not overlap.

On the long-tailed weasel menu we might find mice, voles, pocket gophers, chipmunks, rabbits, or other small mammals. They also eat insects, birds, or bird eggs. In winter they use the same pathways under the snow that mice, voles, or shrews have created to catch their mammal prey. They also follow prey into their burrows as well. A user of scent and sound to find their prey, they often bob their heads back and forth to sense where their prey is located. They probe every crevice or possible place searching on the hunt for a meal. Occasionally, long-tailed weasels will kill more prey than they can eat, and so will store it away for later, just as squirrels or blue jays cache their nuts.

The long-tailed weasel can swim and even climb trees. They also use vocalizations that include purrs, squeals, and squeaks, but usually only when they are disturbed. They are aggressive with intruders in their territory. They may release a musk that is strong smelling when frightened and during mating season.

One of my favorite snowshoe forays was when I followed weasel tracks. The tracks led up to some vole tracks, where the vole tracks disappeared, literally, to never be seen again. Imagine the excitement of discovering a weasel in our own backyard, popping up out of a burrow, or out of the snow after having eaten a vole dinner. It would bring a whole new meaning to the words, “pop, goes the weasel!”

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Aquatic Wonders

2011-03-02T07:01:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

I owe an apology to a gray truck. It was over the weekend, while driving home from Hayward, that I spotted a river otter along the Namekagon River. I turned on the blinkers, braked quickly, and quickly pulled over to the side of the road, perhaps angering the truck behind me. It was irresistible, the opportunity to view an animal that is so amazing and enjoyable, watching them bound across the ice. I had to stop and share the observations with my family!

River otters are part of the weasel family. Comfortable in water, they have a tapered body that streamlines them for successful swimming, webbed feet, sharp hearing and scent abilities, and a sense of touch that gives them good dexterity. Their lungs are complex, with a larger right lung and different lobes in both sides, designed for aquatic breathing. Their airway is also shorter to improve breathing for this diving mammal. Even their mouth is designed well, with sharp canines for biting their prey, and large molars for breaking the hard shells of clams and other mollusks. River otters can dive down to 60 feet deep, can swim underwater for up to four minutes, and move almost 1200 feet underwater. One last amazing adaptation is that they dry themselves by rubbing on the ground, which also maintains the insulation value of their fur.

On land, otters can walk, bound, or slide, which is part of what makes them seem so playful, and what my family observed this otter doing. They slide across the snow or ice, mud banks and vegetated slopes, quickening their pace in efficient travel. They will excavate beaver dams to access water and in winter, use any opening in the ice.

Where do they sleep? Otters create a den or hole at the water’s edge, with many openings that allow them to enter or exit the water in several places. These exits also give them greater access to their prey.
When hunting, river otters will lunge quickly from an ambush to catch their food, or chase after prey. What is on their menu? They will eat small fish while floating at the surface, but take larger fish to the shore for their dining pleasure. Crayfish is another favorite food, according to scat that has been observed. They will also eat frogs, clams, mussels and snails, fruit, reptiles, amphibians, small mammals, and aquatic insects. They even eat plants and birds.

The river otter is more social than most animals in the weasel family. They fish together. They are playful, chasing or wrestling with each other. They will play catch and release with live prey. They communicate with chirping sounds, grunts, or even high pitched screams when mating or fighting.

I envy those who live along the water and have the occasional or frequent observations of this lively and fascinating mammal. Please post your own otter stories at the Museum’s blogspot listed below to share the wonder of this amazing creature that lives in our own back yards.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Pine grosbeak

2011-02-23T11:42:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

This past week my parents have had a special visitor at their bird feeders. It began for them as a flash of slightly different colors – a rusty head and rump, gray underneath, with two white wing bars. Out came their bird field guide to identify their guests as pine grosbeaks, and in this case my parents have been hosting first-year males.

Pine grosbeaks spend most of their time in the boreal forests of Canada, but their wintering areas are determined by food availability. When food decreases, they move to find the food, creating what we call winter irruptions. These irruptions are not common and are irregular for pine grosbeaks.

Pine grosbeaks flock together in winter, and they often frequent a fruit or berry tree until all of it is consumed. They eat through the fruits by biting it with their sharp pointed beak, discarding the pulp, and crushing the seed. Most of their diet is made up of plants, including buds, seeds, and seeds or fruit of spruce, pine, maple, apple, mountain ash, juniper and grass and weed seeds. They are also awkward flycatchers, catching insects, or even spiders. A breeding pine grosbeak develops pouches in the floor of its mouth for carrying insect and plant food to its young. They also eat snow or drink water every day.

Not as much information is available about pine grosbeaks. Even their populations are not well-known because it is difficult to gather data on this species. The boreal forests of Canada are believed to host most of the entire breeding population of pine grosbeaks and some other boreal bird species. Pine grosbeak irruptions are usually in intervals of five to twenty-five years. How lucky any of us are to have this bird species visit our back yards!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, http://cablemuseumnaturewatch.blogspot.com/ to learn more about our exhibits and programs.

Coyotes

2011-02-17T08:03:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

Its tracks lead down the driveway and off into the woods past our house. The tracks are in a straight line, showing an animal with purpose and a plan. At night, the eerie sound surrounds our house as it filters through the night air. Sometimes the sound is as if from a short distance, and other nights the sound comes closely from across the field. The tracks and night songs are evidence that a coyote family is one of our many neighbors.

Howls, yips, yelps and barks make up the high-pitched, varied calls of a coyote. Heard mostly at dusk or night, the calls are filled with short notes or long rising and falling notes. When a coyote is calling its pack together it howls with one high note, but when together as a pack, they yip and yelp more in continued communication.

What is on the coyote menu? Coyotes do well in so many different environments because they are not too choosy about their diet. They predate on small mammals such as voles, squirrels, rabbits, and mice. They will eat fish, snakes, insects or other invertebrates. They will eat ground-nesting birds, and grouse as well. They also scavenge on dead animals. During late summer and winter, they feed on fruits, berries and other plants.

When I play with our dog Tucker, I often “stalk” him from across the yard. When coyotes hunt a mouse or vole, they will stalk slowly through the grass, using their sense of smell to locate the prey, then leaping upon it. Coyotes can pounce up to thirteen feet and run up to a speed of up to 35 miles per hour. A single animal will chase down rabbits, while a hunting pack or pair will team up to pursue larger prey as big as deer. Pack hunting is more common in the winter, and a pack of adults, yearlings, and young will pursue a deer to exhaustion or drive it toward a member of the pack hiding in the brush.

Coyotes are social animals, playing often. They advertise their location with their sounds and smells. Enjoying home ranges up to ten square miles in size, they are a common animal that surrounds us in the north woods. They are known to us through folklore as being very mischievous animals. They are also an enjoyed part of popular culture, as I remember, having grown up with the spectacular, “100-lives” Wile E. Coyote. Most of all, today, I continually enjoy the sounds of their calls at night. They are aptly named, as their scientific name, Canis latrans, means “barking dog.” They are truly a neighbor to appreciate!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, “In a New Light” photographic exhibit focused on the St. Croix National Scenic Riverway. Find it in Cable at 13470 County Highway M. Also discover us on the web at www.cablemuseum.org, on Facebook, or at our blogspot, cablemuseumnaturewatch.blogspot.com, to learn more about our exhibits and programs.

Not only found in the hall of the Library of Congress

2011-02-09T12:40:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

How does a cooper’s hawk end up in the main hall of the Library of Congress? Is the bird stopping in for a library card? Reading a book is indeed one of the best things, after all! This is also an amazing library, with 32 million books and materials in 470 languages! Could it instead be chasing a meal indoors? The Cooper’s hawk is indeed one of the birds that can be enjoyed not just in one of the most amazing libraries in the world, but also in the north woods.

The Cooper’s hawk is a smaller hawk, quite colorful with red eyes, a dark gray back, and rusty bars on its breast. This hawk is very similar to the sharp-shinned hawk, making it very difficult to tell between the two species. When in flight, Cooper’s have stiff wingbeats with short glides. In hunting, they are quite skilled.

A very skilled flyer, Cooper’s hawks move through tree canopies in woodland habitats. They are often in high speed pursuit of medium sized birds. Some of their preferred dinners include the starling, mourning dove, pigeons, robins, grouse, flickers, and jays. They will also eat chipmunks, squirrels, mice, and even bats, although the western Cooper’s hawk more commonly eats mammals. They also rob nests for eggs. They can eat up to 12% of their own weight in one day. For a 200 pound person we would have to eat 24 pounds of food each day!

Cooper’s are also sometimes unwanted guests at our bird feeders, searching for an easy menu of birds rather than bird seed. When they capture their prey, the hawks use their feet and kill it with repeated squeezing. They also have been observed drowning their prey underwater until it stops moving.

Our north woods Cooper’s hawks prefer dense evergreen or deciduous forests. They spend our winters as migrants in Central America – Ahh, a summer in the northwoods followed by a winter in the warmth of the south. However, this lifestyle may not always be an easy one. A study of over 300 Cooper’s hawks showed that nearly 25% of them had evidence of healed bones, a result of swift flight through a rather challenging forest habitat. Perhaps getting a library card would seem easier! Actually, Cooper’s hawks have become much more common in urban areas, as cities provide them with plenty of pigeons and mourning dove prey.

Visitors to the Library of Congress were lucky to have a lovely view of one spectacular bird. The Cooper’s hawk is indeed a gem, and one we are lucky to share our homes with as well!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its new traveling exhibit in February, "In a New Light" photography exhibit, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

White-breasted Nuthatches

2011-02-03T09:08:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

“Yank, Yank, Yank,” came the sound from the trees near the bird feeder. Looking out, the small bird with clean black, gray, and white markings, became visible, headed down the tree face-first. The white-breasted nuthatch is a favorite for many of us who enjoy them around our homes.

The nuthatch name comes from their feeding habit that includes jamming nuts or seeds into the tree’s bark. They then pound at them with their sharp bill to get the seed inside. Seeds are as much as 70% of the white-breasted nuthatches winter diet, which they cache, or store, under loose bark or in tree crevices. They hide the food with a piece of moss, bark, lichen or snow. During the warm months, the white-breasted nuthatch will eat beetles, stink bugs, gall flies, scale insects, caterpillars, or ants. They have been observed feeding on the ground, and of course, enjoy feeding stations for sunflower seeds, nuts, or suet. When we see the birds making frequent, regular trips to the feeder and returning more quickly than it seems it would have taken them to eat the seeds, the nuthatches are most likely storing those seeds away for another day!

White-breasted nuthatches have some extremely interesting behaviors. As cavity nesters, they will often smear insects around the nest entrance to deter their main competitor for the same cavities, squirrels. When they leave the nest hole, they will also wipe the entrance with fur or vegetation, presumably to make it difficult for predators to smell their presence.

During the winter, white-breasted nuthatches travel with mixed flocks of other birds such as chickadees, titmice, red-breasted nuthatches, and downy woodpeckers. Scientists believe that chickadee calls carry information about predators, offering protection and a means to find food easier.

If we are to go looking for a white-breasted nuthatch, they are most commonly found in mature, deciduous forests, while the relative red-breasted nuthatch prefers the coniferous forest more. Explore and enjoy the wonder of this nature in your own back yard.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Goldenrod Gall

2011-01-26T07:33:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

As I was walking down the road, the goldenrod stalks were waving in the wind. In late summer, the yellow colors of the goldenrod lights up the fields and roadsides. Now, its dead stems sometimes show life, with a round ball evident on some of the stems. This round ball is an insect gall, the home of a small fly spending the winter protected inside this plant. My body shivers in the cold, just thinking of what it might be like to be an insect inside that small ball, tucked inside a plant. What an interesting place to spend the winter!

A goldenrod gall is formed by a small fly, a fruit fly. The insect’s relationship with goldenrod began last spring when a female fly laid one egg in May to early June on the leaves of a goldenrod stem. After four days, the egg hatched and immediately the young larva chewed into the stem. The larva injected chemicals into the plants, causing cell division to increase and form the round gall. Its hard corky exterior protected the inner nutritious starches that provided food for the larva. As the gall grew, the fly larva created a central chamber that it lived in until the next spring. During the summer, the white larva fed on the inside of the gall, growing until early October. Since the adult flies have no mouthparts with which to chew, the larva then chewed a tunnel out to the surface of the gall, leaving a thin protective exterior over the outer opening.

During the winter, the mature larva went into a diapause, or dormancy. As winter approached, the water content in their bodies was converted from glycogen into glycerol, acting as antifreeze to keep ice crystals from forming in their bodies. Additionally, they had the plant gall to provide physical protection from predators.

In the spring, the fly larva will leave its dormant state and pupate inside the gall. Once it emerges as an adult fruit fly, it will crawl along the previously created tunnel, inflate a balloon-like body part between its eyes to create an opening in the thin covering, and escape its winter home. As an adult, the fly is smaller than a house fly, and lives about ten days. The cycle then begins again.

The goldenrod gall is not harmed by the insect’s presence. It seems like an ideal, and amazing, way for a small insect to survive and adapt to the harsher elements of our winter season. However, the small fly is still susceptible to dangers. Downy woodpeckers and chickadees are known to feed upon the insect larvae. Two species of parasitic wasps deposit their eggs through the growing gall tissue into the fly larvae, so that a small black wasp may emerge in spring instead of a fruit fly.
Wander the snowy fields in search of some goldenrod ball galls. Take a closer look at one of nature’s amazing delights. Enjoy nature in our own back yards.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

At the Feeder

2011-01-20T07:05:00.000-08:00

By Susan Thurn,
Cable Natural History Museum

At the Feeder

Much activity has been at the bird feeders this past week, and one of my favorite views and sounds came from observing the mourning dove. Their gentle woo-oo-oo-oo sound made from their cooing perches that gives the bird its name can comfort us, and the rapid flight on whistling wings is pleasant when they burst into the air.

Mourning doves feed mostly on the ground, swallowing seeds to store them in their enlarged esophagus we call the crop. One mourning dove was found to have over 17,000 seeds in its crop. Once they are finished feeding, they fly to their safe perch for digestion of their meal. Wild seeds, grasses, herbs, cultivated grains, and the occasional berry make up the most of this dove’s diet, with a once in while meal of snails. The birds peck or push aside ground litter while searching for food.

Known as a lover of baths in the sun or rain by lying on the ground or on a tree limb, mourning doves stretch out a wing, holding it in place. Our bird baths and shallow pools of water are also bathing places, and the doves will bathe in dust as well. They will often gather at their drinking spots at dawn or dusk. The bird drinks through suction, not needing to lift their heads.

Adult mourning doves feed their nestlings "pigeon milk," milk secreted from their crop lining. This food is fed to the hatchlings for three days, more nutritious than cow or human milk because of its protein and fat. Except for during the breeding season, the doves roost communally in conifer or deciduous trees, spending more time in them on colder winter days. Take a walk outdoors, and look for their roosting areas, listen to their mournful morning call, and enjoy the beauty in our own back yard.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Where Do Birds Sleep

2011-01-12T11:40:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

One of my favorite Christmas presents this year was the gift of a new mattress. I was pondering the other day, as I just woke up from a long winter night’s sleep, what is a night’s sleep like for a bird? How do they keep themselves warm? How do they survive such cold temperatures? Do they nest? Find other places to sleep? Whatever they do, a bird’s sleep could not compare to the comfort and warmth of my new memory foam bed!

Many people assume that birds use their nests during the winter, but a nest is a baby’s crib, something to be used during the spring rather than winter. However, some birds do use our human-made bird houses to sleep in for the night. Birds like woodpeckers, nuthatches, and other species curl up inside tree cavities for cover and heat. Many owls and other cavity-nesters find their favorite tree holes. Other birds crowd together in whatever nooks or crannies they find.

Our favorite, cheery goldfinches, sleep in thick evergreens, as do some sparrows, crossbills, snow buntings, and sometimes the chickadee. Songbirds such as blue jays and cardinals find dense thickets in which to sleep within. Crows and turkeys roost in trees. Crows sit close to the branches in their roost, feathers covering their feet, tucking their heads beneath their wings.

Some birds that prefer open fields will burrow into snow holes to escape the wind and cold. Ruffed grouse will dive down from the aspens in which they feed during the day to the deeper snow below, allowing the snow to insulate them from the colder night temperatures.

Some ducks sleep in icy water. Bobwhites sleep on the ground, heads facing outward to conserve body heat while protecting them from other dangers.

Wherever a bird sleeps, its first protection is from its feathers. Feathers repel water and insulate birds’ bodies from the cold. Using muscles, birds can raise or lower each feather, fluffing them to create warm air spaces. Burying their heads and feet also reduces heat loss.

Occasionally as I take a walk at dusk around the house I will pick up on the commotion as birds are settling in for the night. I keep my eyes open for the birds as they are getting ready for sleep. I wish for them sweet dreams and success throughout the night, and I appreciate my cozy warm home just that much more!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Blue Jay

2011-01-06T08:21:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

“Jay! Jay!” is a familiar sound around our bird feeders. These blue jays are identified by their perky crests with blue, black and white plumage. Seeing them in large groups around our feeders is not uncommon. Find out the following information about these intelligent birds worth getting to know better.

To understand a blue jay's mood, just look at its crest. If it is up, this suggests a stressed or aggressive bird.

Blue jays are primarily vegetarians, eating mostly nuts, fruit, grain and seeds from trees and shrubs. They especially like acorns. They also eat small invertebrates such as beetles, caterpillars or grasshoppers. Having a reputation for raiding nests for eggs or young birds, studies have actually shown that this behavior is less common. Jays hold their food in their feet while pecking at it.

Blue jays store food in caches during the fall so that they may eat the food later in winter. They can carry food in their throat and upper esophagus, an area called a “gular pouch.” This “storage method” can allow jays to store one acorn in their bill, one in their mouth, and up to three acorns in their pouch. Six blue jays fitted with radio transmitters each cached up to 5,000 acorns in one autumn! It is no surprise this bird has the reputation as being a re-forester of the oak tree.

Blue jays have been observed "anting," rubbing their wings with ants. They even lose their balance as they are doing this. Why do they do this anting behavior? Scientists believe the substance from the ants can repel parasites, or perhaps help clean the feathers.

Some blue jays migrate, while others stay put all year-round. Migrating flocks of up to 250 birds have been observed flying over hawk-watching spots. The groups have included adults and young birds, but there seems to be no age difference between migrating jays and those that remain as residential birds. Some jays migrate one year but not the next. Scientists believe that the amount of jays that migrate is less than 20 percent. This migration continues to be quite a mystery.

The striking blue color with the snow as a backdrop makes a delightful winter sight. Our resident blue jays are fun to have around, and their sounds a joyful greeting to our ears. Be sure to get outside this week to enjoy what winter brings!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Orion

2010-12-29T09:52:00.000-08:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

The longest nights of the year are upon us, but at least we’re past the solstice and days begin lengthening again. With the addition of a new dog in our family, I find myself outdoors at night more often than previously. These walks are pleasurable for in spite of the cold, there is an amazing night sky to greet me. Even in early evening, sky-watching is worthwhile, as Orion, a constellation we see only in the winter, is peeking into view as night falls. Sirius, the brightest star in our night sky, also sparkles in the south. It makes for a lovely view!

Orion, known in historical legend as the hunter, shines in prime time during winter's long nights. It can be viewed in the east soon after nightfall. It is perhaps one of the most easily found and identified constellations we can view. Bright stars make up Orion’s three-star belt. Around the belt at similar distances are four bright stars that make up the outline of the hunter’s body. An orange star named Betelgeuse is Orion’s left shoulder, and a blue star named Rigel is brightly showing Orion’s right foot. Moving down from the belt is a small line of three stars that create the hunter’s sword, although technically the middle star is not a star but the Orion Nebula, which can be seen with binoculars as a glowing cloud of material. Sirius, the bright star to the south, is part of Canis Major, the big dog or big dipper.

Orion, the hunter, stands by other night constellations such as the river Eridanus, is accompanied by his faithful dogs, Canis Major and Canis Minor. Together they are said to hunt celestial animals such as Lepus, the rabbit, and Taurus, the bull. There are many stories in different cultures of how Orion came to be in our night sky with his dogs. In Greek mythology, Orion was in love with Metrope, a seven sister who forms the Pleiades constellation. Unfortunately, Metrope did not return his affections. Orion’s tragic life ended when he stepped on the scorpion, Scorpius. The gods then felt badly for him and put him and his dogs in the night sky, along with animals he could continue to hunt. However, Scorpius was placed far away from Orion in the night sky so that Orion could not be hurt again. Hungarian tradition also calls him a hunter, but believes that he is the father of Hungarians. The Chinese thought the three stars were a top a man’s head. Australian aboriginals believe Orion is called Julpan, a canoe. They tell the story of two brothers who went fishing, and caught and ate a forbidden fish. Seeing this, the sun sent a waterspout that carried the two brothers and their canoe up into the sky. Native Americans from a tribe in California thought that the three stars were the footprints of the god of the flea people. This legend states that when his five wives ran away because they were itchy, three times the god of the flea people looked in the sky for them. When his footprints are seen only in the winter months, the flea people go into hiding, a time when there were no fleas. Sumerians thought the pattern was a sheep, and Betelgeuse, meaning armpit, was the armpit of the sheep.

There is more than just Orion to take a peek at in our night sky this time of year. On December 29, the thin crescent moon rises in the southeast with the planet Venus to its lower left. Our Christmas star, Sirius, rises around 7-8 p.m. and is worth looking at with binoculars, as when it’s low in the sky it twinkles in flashing colors. In early January, Uranus and Jupiter can be viewed with binoculars. These are all sights worth getting outdoors in your own back yard!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Balsam Fir

2010-12-23T07:09:00.000-08:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

As we head into one of our biggest holiday weeks, some of my most favorite sights and smells include the lights and the smell of our holiday tree, a beautiful balsam fir. The history of the Christmas tree has many interesting and different stories. The Egyptians might not have celebrated a holiday with a fir or pine, but were part of a long line of cultures that treasured and worshipped evergreens. In fact, when winter solstice arrived, they brought green date palm leaves indoors to symbolize life's triumph over death.

Another balsam fir holiday story is associated with a German, St. Boniface, who cut down an oak tree in order to disprove the legitimacy of the Norse gods to the local German tribe, and was amazed when a fir tree sprung up from the roots of the oak. Another cultural tradition included a tree that was taken to the town market center and lit aflame to celebrate the holidays. Yet another story of the tree includes the decoration of a small tree with nuts, apples, pretzels and paper flowers for the children. Germans and Scandinavians placed evergreen trees inside their homes or just outside their doors to show their hope in the forthcoming spring. No matter what the celebration, today the balsam fir is still a perfect tree as it has the benefit of not shedding its needles when they dry out, as well as retaining good color and scent.

What is special about balsam fir? It’s a great tree to shake hands with, with very soft, individual flat needles. Balsam fir bark is thin, gray, and smooth except for numerous blisters on younger trees. The scientific name "balsamea" is so named because of the many resinous blisters found in the bark. These balsam blisters contain a sticky, fragrant, liquid resin and so they are sometimes called “blister pine.”

A balsam fir provides food and cover for red squirrels, moose, snowshoe hares, deer, ruffed grouse, crossbills, and chickadees. The needles are also eaten by some caterpillars. Porcupines eat the seeds.

The balsam resin has been used to produce Canada balsam, a type of turpentine, and was used as a glue for glasses, optical instruments, and for preparing microscope mounts. It has also been used as a cold remedy and an EPA approved nontoxic rodent repellent. It is a tree of many uses!

I don’t have to enjoy the tree in my living room, as balsam fir grows commonly in the forests around us. Be sure to get outdoors this holiday season and shake hands with a balsam fir!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Mistletoe

2010-12-15T13:41:00.000-08:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

Having just celebrated six months of wedded bliss, this holiday season brings on great feelings of love and opportunity for family celebration. It is a time filled with candy canes, colored tree lights, and mistletoe, just a bit of the many things we can enjoy at the holidays. I’ll never forget the time I was preparing a lesson plan for area schools on symbiosis, a word that describes the relationships between organisms in the natural world. I discovered then that mistletoe is a parasite. Mistletoe, a parasite? I always thought it was so ironic that a plant that brings love and joy into our lives was also a plant that uses other plants as a host by taking nutrients out of the tree. What a surprise!

Mistletoe is a partial parasite, as the plant is still capable of photosynthesis. They have a special root system, called haustoria, which grow down into their hosts. They extract nutrients from the trees upon which they grow.

The common dwarf mistletoe grows in northern Wisconsin. Not looking like most mistletoe plants we hang in our homes, this dwarf plant grows less than 3 centimeters tall. In spite of its size it often causes a very conspicuous irregular growth known as a “witch’s broom.” A witch’s broom is created by the mistletoe as it causes the tree to grow a compact mass of branches that resemble a broom that can reach 3-10 feet in size. Its main host is black spruce, but it also will parasitize red, white, and jack pine and balsam fir.

To some, mistletoe might be considered a negative part of a forest, but actually mistletoe does have some benefits in many ecosystems. The density of the growth can provide habitat to birds and other animals. Some species of mistletoe can cause the host plant to grow more berries, increasing reproductive success and providing food to other animals.

Mistletoe has a history that is rich in human tradition that goes all the way back to Greek culture. Throughout time mistletoe was thought to bestow life, protect against poison, and increase fertility. It was also thought to ward off evil, or bring peace, as well as provide a prediction of happiness and long life. Mistletoe can certainly bring magic to this season’s holiday joy. May you all enjoy a wonderful, festive holiday, and be sure to find your way under the mistletoe!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Barred Owl

2010-12-08T07:22:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

I’ll never forget the time I called in a barred owl using my voice, only to have both the owl and myself experience being dive-bombed by woodpeckers. Or the other time I called in five owls all part of the neighborhood around the house. I’ve been practicing a barred owl call for many years now, and its who-cooks-for-you song is noticeable enough in the forest to make it one of the most-known owls in our northwoods environment. It is with constant amazement and utter respect that I interact with these birds in our area.

A barred owl enjoys a variety of habitats that include deep, moist forested areas, wooded swamps and woodlands near wetland areas, preferring larger forest tracts. Their territory is thought to be up to one square mile of land. Barred owls eat small mammals such as voles, mice, shrews, squirrels, rabbits, and chipmunks. They also will eat birds up to the size of a grouse, woodpeckers, and even smaller owls, and are known to take prey from around bird feeders. They catch birds as prey at dusk when the birds are settling in to roost for the night, as the barred owl cannot usually take them while in flight. They also will eat bats, snakes, frogs, salamanders, mollusks, and insects. They have even been observed wading in water in search of crayfish and fish. In fact, the feathers on the front belly of the barred owl can sometimes have a pink tinge, possibly due to eating crayfish. In winter, barred owls rely on their excellent hearing to focus in on animals burrowing through snow.

Barred owls hunt mostly at dusk and night-time by sitting on a high perch and looking and listening for prey. They then catch their prey during a short flight to the ground. During the day they hide in dense foliage, usually high above us. They also roost on a branch close to the trunk, or in a natural tree hold.

A very territorial bird, barred owls use vocalizations that are more extensive than their familiar who-cooks-for-you. When feeling very territorial, they move from a short bark into a monkey-like call that is amazing to hear. To me these owls represent one of the best creatures of the northwoods. Their beauty, their night call, are all worthy of admiration.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

White/Black Fur

2010-12-02T11:55:00.000-08:00

Nature Watch
December 3, 2010
By Susan Thurn,
Cable Natural History Museum

If the color black absorbs heat, why is a polar bear white? It turns out that dark or black fur isn’t always the warmest fur to have. Energy does come to animals when the sun is shining. This solar radiation penetrates into the fur, some of which is absorbed at the surface, and some all the way to the skin.

Because our winters have less sun, we have less incoming solar radiation, called insolation. Animals living in our region and latitude are exposed to a lower amount of insolation. Black fur absorbs solar radiation well, but even then, much of the energy is redirected back into the environment again, keeping the sun’s heat from reaching the animal’s skin. A contrast to this is white fur, which reflects some sunlight outward, but also reflects the sun down into the fur layer down to the skin. Add to this the thickness of the fur and how those fur pieces lay over each other, this white fur can more successfully warm the skin. Animals that have dark skin with white fur (as do polar bears) increase their ability to absorb heat. How interesting that white fur is not just about camouflage!

How do humans deal with constant exposure to cold? Can we, who live in the northwoods, ever get “used to the cold”? Evidence does show that humans can acclimatize themselves to colder environments, but usually only with prolonged exposures to that cold. Several groups of people have developed very specific adaptations to cold. Inuits, Norwegian fisherman, and Tibetan and Indian yogis have increased circulation and skin temperature in their extremities. Finnish outdoorsmen can have brown fat in strategic locations. Mailmen of Quebec City have lowered blood pressure and heart rates. Antarctic workers have a higher core temperature. Those with yoga training can exhibit a higher cold tolerance.

Sign me up for the next yoga class! And the next time I feel bad about the extra layers of fat around my body, I’ll just think of it as strategically located cold insulators. Whatever it takes, being outdoors, even in the cold, is worth making some adaptations!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Cottontail Rabbit

2010-11-24T07:21:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

One morning this week my husband and I looked outside and saw a cottontail rabbit feeding right outside our window. The little white burst of color we call a tail resembles a cotton ball for which the rabbit is named. The cottontail’s body was covered with a soft pale-gray mixed cinnamon colored fur with black tips. The rabbit living in our backyard was grooming itself, as their fur isn’t waterproof and needs care to keep their hair in healthy condition. Their large, long ears shifted as a satellite dish as they listened to everything around them. All of these observations were made in a few moments, watching this rabbit outside our window.

The sun was not even up yet when we saw our backyard visitor. Cottontail rabbits browse for food at night on grasses and herbs such as clover, dandelions, alfalfa, fruits and vegetables. In winter, their diet consists of the woody parts of bark, twigs, brambles, and buds of birch, oak, basswood, willow, sumac, dogwood and maple trees. Their teeth are adapted for gnawing on plants. Their top incisor teeth keep growing constantly throughout their lives to allow them to keep chewing away at their meals.

Cottontail rabbits live in a variety of habitats from our neighborhoods, orchards, and farms to sparsely wooded or thick brushy areas. They can travel in a range up to eight acres, and can be moving any time of day or night, but mostly during dawn and dusk. They choose areas with good protection and escape routes.

Freeze tag was always one of my favorite games, and it is one that the cottontail rabbit excels at when avoiding predators. Freezing is far more than a game to these rabbits, as they use this technique to avoid predators, avoiding being noticed until the animal gets too close. Then they shoot out like a bolt of lightning, fleeing from their prey with a zigzag pattern, reaching up to 18 miles per hour and leaping up to fifteen feet away in one move. The zigzag movement gives them an advantage as it breaks their scent trail. Sometimes they will also stand on their hind feet to observe predators.

We all know the cottontail rabbit can sometimes be a bit of a scoundrel to us as they chew away our tulips, but they too can bring great enjoyment in our backyards. Be sure to post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Ruffed Grouse

2010-11-18T08:15:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

While walking in the woods this week it happened again. I was meandering along and enjoying the shades of brown and green colors that greet us in the forest this time of year. Suddenly, I was startled and almost jumped out of my skin when a ruffed grouse flushed out of the brush nearby. I enjoy these birds for their beauty, in spite of the scare they often give me. They are difficult to see as they camouflage themselves so perfectly into their surroundings. As they flush out away from me, the sound of their wings beating loudly as they swiftly fly away matches the speed of my startled, crazy heartbeat.

Some fourth graders I know are currently reading the book Hatchet, by Gary Paulsen, which features a ruffed grouse. In the story, Brian Robeson has managed to survive a plane crash in northern Canada, and is surviving this northwoods wilderness with his wits and a hatchet. Brian names the ruffed grouse “foolbirds.” I have to disagree with Brian’s “name,” as ruffed grouse seem to me anything but foolish. The way grouse find food anytime during the year seems very intelligent to me.

In autumn, there is plenty of food available to a ruffed grouse. There are many different fungi, or mushrooms, to choose from, as long as the birds can find them before the red squirrels. Acorns have fallen from trees, and grouse benefit from white-tailed deer who have stomped on the acorns and broken them open to be found and consumed by the birds. The late-ripening berries are for the taking, and its not just the shrubs and other plants we typically think of that have available fruits, but also low growing plants such as rose hips, bunchberry and wild lily of the valley.

In later fall, the ruffed grouse adapts to new food sources as the bird moves from the ground to the trees. Grouse consume the buds of many different trees such as aspen, birch, and chokecherry. It is believed that with the change to higher fiber-filled tree parts, grouse depend more on micro-organisms in their digestive system to aid them in getting nutrients out of their food.

We are fortunate to be able to enjoy the beauty of ruffed grouse in the northwoods. On second thought, perhaps “foolbird” is an appropriate name, because they sure do fool me with their excellent camouflage and ability to hide. Be sure to get outdoors this fall to enjoy looking for grouse in your own back yard.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Fox Sparrow

2010-11-10T09:05:00.000-08:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

The bird feeders at my parent’s house are still busy in spite of the many migrant birds that have left us for a while. A few glances at the feeder show the less colorful winter plumage of the goldfinch, the slate-colored juncos, chickadees, downy and hairy woodpeckers, white and red-breasted nuthatches, blue jays, cardinals, mourning doves, white-throated and fox sparrows. It was the fox sparrows that recently caught my eye, and ears. A larger sparrow, fox sparrows are bright rust-colored on the tail and wing. There are red, thick streaks on the breast, and reddish streaks on a gray colored back with faint white wingbars. Their lower mandible is colored pink to yellow-orange. These sparrows are a striking bird, and have some additionally interesting behaviors.

Fox sparrows most appealing behaviors are ones to hear, rather than see. They scratch through leaves through insects and seeds, and make so much noise they sound like a larger animal. These noticeable actions come from a vigorous double-scratching as the fox sparrow kicks backward in the litter with a two-footed jump-kick motion as they work to uncover food. This same foraging behavior unfortunately makes them vulnerable to cats and other predators.

The main food choices of fox sparrows are seeds from grasses and a plant called smartweed. They will eat berries as well. During warmer seasons, they also eat insects and feed them to their young. When nesting, adults are known to perform a broken-wing display to lure potential threats away from the nest.

Be sure to enjoy the fox sparrows around your own feeders, birds which are collectively known as a “den,” or “slyness” of sparrows. Enjoy them while you can though, as they spend our winters in the warmer climates of North America. Their migration this season began in early October and by mid-November, only the last few will remain in our neck of the woods. Watch and listen for this last glimpse of color and sound as they scratch around the fall leaves of our northwoods backyards.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Fall Leaf Decomposition

2010-11-03T08:10:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

“Scrunch,” “scrunch” went the crunch of dry leaves under my feet. The brown, dead leaves have been a delight for many that love to walk through leaf litter while kicking up fall leaves. For others, the leaves are perhaps part of a fall routine as people rake them from their lawns. For nature, decomposition is the natural process for leaves as they fall to the ground, creating new building blocks of life recycled over again. Right now in the forest this recycling is a job filled by invertebrates, fungi and bacteria.

Decomposition of leaves occurs through many different means. Invertebrates and earthworms break leaves into smaller fragments. This process allows the leaf pieces to have more surface area to support the next step of decomposition, bacteria and fungi. Rain also filters through the leaves, dissolving chemicals and nutrients. Bacteria grow better when the leaf fragments are smaller. The organic matter is broken down to carbon, nitrogen and other minerals.

Certain species of fungi also aide with the decomposition of leaves. Fungi hyphae fibers spread through dead leaf litter just under the forest floor, extracting nutrients the fungi need to survive. These hyphae develop into matted carpets that we sometimes see when leaf litter is moved. The speed at which decomposition occurs depends on moisture, temperature and composition of the leaf matter. Lower temperatures make decomposition occur more slowly. Leaves with low nitrogen also slow decay because the fungi cannot gain enough nitrogen from the organic matter to make necessary proteins. Lower oxygen environments also slow decomposition.

Waste not, want not is the perfect description of our leaf decomposers. Without them, nitrogen and other nutrients would be locked in the dead leaves, not leaving enough for living plants and their needs in making new leaves and seeds. Those bacteria and mushrooms are such “fun-guys!”

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Turning

2010-10-28T11:54:00.000-07:00

Nature Watch

By Susan Thurn
Cable Natural History Museum

Chilly fall days give us a warning that winter is coming, and in response plants and animals (including we humans) adjustment accordingly.

The changing of the season also affects the behavior of bodies of water. You may have heard people referring to lakes “turning” this time of year, and wondered what that means.

It’s a twice-yearly phenomenon related to water and air temperature—here’s how it works: In late summer, lake surface waters reach their annual maximum temperatures. Deeper waters are cooler—in many lakes, there is a definite stratification or layering of water temperatures that you would feel if you were swimming on the surface and then dove down deep. The warmest, least dense waters lie on top; water temperature decreases with depth, reaching its minimum temperature at the greatest lake depths.

In the summer, a deep lake will have three layers in the water column: the upper, warmest water (the epilimnion); a thin middle layer, where temperatures rapidly decrease (the thermocline or mesolimnion); and the deepest, coldest water (hypolimnion).

In autumn, cooler air temperatures and diminished hours of sunlight result in a loss of heat from the lake’s upper water layer. As these waters cool, they become more dense and when they reach about 50 degrees F, they sink into the middle layer below, erasing the temperature stratification that had developed during summer.

Eventually, all the lake water reaches a uniform temperature, and surface winds then mix all the water. When the winds are strong and fairly constant in direction for an extended time, they establish a water circulation pattern—as surface waters are blown downwind, waters from below must rise along the upwind shore to replace those waters pushed across the surface. To complete the circuit, the downwind shore surface waters, piled up by the wind, sink to replace the rising bottom waters.

In time, the resulting circulations will completely overturn and mix all the lake’s water—hence “fall turning.” The phenomenon can at times produce a rotten-egg odor, since the deep waters, which are low in oxygen and high in sulphur, rise to the surface and release sulphurous gases into the air. The turnover also mixes atmospheric oxygen into the lake water, replenishing the oxygen in deep waters and allowing fish to return to the depths where many will spend the winter.

Of course, after the fall turning cools the lakewater and as winter approaches, surface waters approach the freezing mark. Unlike most compounds, water reaches its maximum density as a liquid just before becoming a solid. Under normal conditions, freshwater is most dense at 39 degrees F, and ice, being less dense than liquid water, floats. So as lake waters cool, they sink when they reach 39 degrees. Colder water remains above, and is eventually covered with ice.

In the spring, the cycle happens again in reverse. Ice cover melts, and cold surface waters warm until they reach the temperatures of the bottom waters. Winds blowing over the lake again set up a full circulation system; as warming continues, the three water layers again become established, and a full turn of the cycle is complete.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Northern Pike

2010-10-20T08:00:00.000-07:00

Nature Watch

By Susan Thurn,
Cable Natural History Museum

They were trolling the waters for a big fish, the musky. “Fish on,” were the words heard from the boat as the sound floated across the water. It was a decent sized fish, but it wasn’t a musky. Instead, it was the struggle of a northern pike that was brought into the boat. This tooth-filled mouth earns its place as the second largest predator fish in northern Wisconsin.

Northern Pike have a duck bill shaped long snout that is lined with sharp canine type teeth. Their olive-green upper sides are marked with longitudinal rows of yellow spots. This “handsome-looking” fish can live for more than 20 years.

The northern pike is a cool-water species whose habitat is usually warm, slow, and shallow, heavily vegetated rivers or the weedy bays of lakes. They also can be found in cold, clear, rocky water bodies. A solitary and territorial fish, northern pike ambush their predators, laying in wait at the edge of weed beds to dart out, attacking with surprising speed. Young northern pike feed on immature aquatic insects and then fish. Adults will eat fish, crayfish, ducklings, muskrats, frogs, leeches or mice. Northern pike are known for being less particular about their food choices. They will even eat younger pike fish, making it critical for the young pike to find safe shelter among vegetation. Northerns typically catch their prey sideways, immobilizing their prey with the backward pointing teeth, and then turning the prey headfirst so they can swallow it. Younger pike have been found dead having choked on a pike of a similar size.

It may be that the catch and release fishing of my family has been the best way to catch glimpses of a northern pike. A swirl or swish at the water’s surface makes me take a second look, hoping for a view of a fish. These fish are just one of the many enjoyable experiences we can look forward to experiencing in our northwoods back yard.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Slugs

2010-10-13T09:00:00.000-07:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum
“I’ve been slimed!” That’s the comment that came out of my mouth this week as I discovered a host of slugs underneath the log I had just lifted. With the rain we have had this summer and fall, the slugs seem to be more easily observed. It is not just their slug trails that are fascinating to learn about.

Slugs and snails are related and are called gastropods. Like other land snails, most slugs have two pairs of 'feelers' or tentacles on their head. The upper pair senses light while the lower pair is their sense of smell. When disturbed, they retract either pair, and if damaged, they can re-grow the tentacles. Slugs move through muscular contractions on the underside of their foot. Slugs feed on plant materials with a rasping, specialized mouthpart. Slugs can stretch their bodies to 20 times their normal length, allowing them to squeeze through the tiniest spaces to get to their food. They produce mucus to assist them with movement. The mucus secreted by their foot contains fibers to keep the slug from slipping down steep surfaces. Their bodies are made of mostly water, so their soft tissues need to always stay moist. A thicker mucus coats their entire body for protection from elements and predators. When attacked, slugs can contract their body, making their bodies more compact, which when combined with the slippery mucus, makes it difficult to grab. The mucus also is distasteful as a deterrent. For us, just touching this slime can be a deterrent!

The slime trail slugs leave behind has other effects than just assisting with transportation. A slug can use its own trail again and again to find its way around. Other slugs recognize the trail as their own species, leading to success in finding a mate. The trails can also be used by other slugs to find a good plant food source. Carnivorous slugs will also use the trails to find other slugs as a meal. Finally, many slugs will secrete slime cords to lower themselves to the ground.

Slugs feed mostly at night, seeking shelter during the day in soil or under leafy debris. They become more inactive during dry, hot weather, and more active after rain because of the moisture. In drier conditions, they hide in damp places such as under leaves, tree bark, logs, rocks, and man-made structures to retain their body moisture.

Fall is a great time for slugs. This time of year they lay up to fifty eggs in the soil, where the eggs will wait through winter or sometimes for years until moisture conditions are right. Their egg clusters look like colorless jelly. During the winter, some slug species overwinter in hibernation under ground while with other species, the adults die in the autumn.

To some gardeners slugs are considered to be pests because of the destruction they can create in our gardens. However, many slug species play an important role in our ecosystem by eating decaying plant matter. Some slugs eat other slugs and snails, earthworms, or even carrion. They are also food to snakes, salamanders, turtles, birds, toads and even humans. Explore your own back yard, as you never know what slime trails you might run into!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Fall Color Pigmentation

2010-10-09T09:20:00.000-07:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

As we go through another peak season of autumn colors, the mornings begin with a blaze of color as the sun shines on the leaves, and the night’s silence brings comfort and solace. The colors this year were golden! But just what do all those colors do?

First we have the magical chlorophyll, the special ingredient that converts sunlight into sugars. Chlorophyll absorbs red and blue parts of the light spectrum, so it reflects to our eyes as green. Just as sunlight can fade our fabrics colors, or damage our skin, sunlight also causes chlorophyll to break down. Green plants continually create new chlorophyll throughout the warm summer. Fall’s cooler temperatures slow down chlorophyll production, which is when leaves begin showing other colors than green.

The orange color we have seen so much of this fall season is the same color of many fruits and vegetables such as tomatoes, carrots, sweet potatoes, marigolds, pumpkins and even egg yolks and butter. These orange pigments are called carotene. In our bodies, carotene is essential for normal vision, for healthy skin and organs. It is believed to have protective properties against some types of cancer, and against ultraviolet rays of the sun. In plants, carotene absorbs sunlight energy, but instead of photosynthesizing like chlorophyll, it just passes the energy on to the chlorophyll. Carotenes are not damaged as easily by sunlight, so when chlorophyll disappears from the leaves in the fall, the carotene color is left behind for a longer time.

Finally, there are the anthocyanins, which show red and purple colors. These pigments are formed when plant proteins interact with sugars inside the plants cells. The colors formed are based on their acid levels. If the sap in the cells is acidic, the red colors will be brighter, and if less acidic, the color will show more purple. Anthocyanins do not play a part in photosynthesis, so there is some debate over what their purpose is in the leaves. Some believe that they provide a sunscreen for the leaves, allowing the leaves to reabsorb nutrients before they drop to the ground. Anthocyanins are also water-soluble, so can change the freezing point in the leaves, and so may protect a plant’s water supply. Blueberries and so many other fruits and vegetables are filled with anthocyanins, and also have healing powers. Whatever their role, they bring beauty to the colored autumn horizon.

Such a treat another fall has brought us. It brings joy to our eyes, and the rustle of the drying leaves brings a different music to our ears. Additionally, they can bring a variety of colors in our yard, gardens, and kitchens! Enjoy the benefits of these pigments in our foods, and enjoy the wonder of the seasons from our own back yards!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County

Chipmunks

2010-09-29T09:44:00.000-07:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum
Walking down the sidewalk, I heard a rustle in the undergrowth of the flower garden. I smiled when out zipped one of the chipmunk family living in the yard. Its puffy cheeks looked almost as big as its body as it crossed my path and scurried down into its tiny hole. These lively critters pudgy cheeks, stripes, and bushy tails have made them famous even in Hollywood, and for good reason.
Chipmunks eat a variety of foods including seeds, nuts, fruit, berries, fungi, insects, worms, bird eggs and nestlings, small frogs and sometimes even small mice. They gather food in areas where they can hide from their predators, and then store their food into their cheek pouches to carry to their burrow. This mammal’s scientific genus name is appropriate - Tamias, which in Greek means "storer," a behavior that this animal does so well as they collect and store food for a “long winter’s night.” Chipmunks can climb trees to harvest acorns or hazelnuts, but prefer foraging on the ground. They often spend sunrise to sunset searching for and storing food, harvesting as much as a bushel of nuts in just a few days. In August, chipmunks begin stockpiling these tasty treats in their burrows in preparation of winter. Chipmunks hibernate, but instead of storing fat like bears, they occasionally feed on their cache of nuts and seeds.

Chipmunks dig burrows with entrance holes about two inches in diameter and more than thirty feet in length. The main entrance can be found near stump or rocks, well-concealed from predators. Additional secondary entrances can exist in open areas, all part of an interconnecting underground system. The passages are two or three feet below ground. Their sleeping quarters are filled with shredded leaves and kept extremely clean. Food storage areas are in the lower tunnels to keep “refrigerated,” and leftover food shells and feces are stored in refuse tunnels. Now that is a well-planned home!
Chipmunks are important in a forest ecosystem. Their harvesting and caching activities help re-seed plants. They distribute spores of different fungi as well. They also can bring enjoyment into our lives. I know many Museum friends who enjoy chipmunks at their feeders, watch them run over their toes, and even name the often friendly creatures. Please share your own chipmunk stories at the Museum’s Nature Watch blog, at cablemuseumnaturewatch.blogspot.com.
For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Mushrooms

2010-09-22T09:30:00.000-07:00

Nature Watch
By Susan Thurn,
Cable Natural History Museum

Our recent rain has been a mushroom lover’s delight. With so little rain the past few years, mushrooms seemed almost scarce in comparison. Now, when we walk through the woods we are greeted with a rainbow of colors, shapes, and sizes of amazing mushrooms. Of course they are of interest for their delectable tastes, and receive attention because of their additional ability to make those that eat the wrong mushroom extremely ill! Maybe we are more accustomed to noticing them when they are on our plate, or growing in our refrigerators. Still, they are worth our attention as we explore outdoors.

Mushrooms belong to the fungi kingdom. They cannot photosynthesize so must feed mostly on organic material. Their amazing success in reproduction is through spores, which is one reason we can find them almost anywhere. They are made up of microscopic root-like threads called hyphae. Their cell walls are made of chitin, the same material making up the shell of a crab, lobster, or dragonfly. Unlike humans who ingest their food and then digest it, a fungus digests its food first with the use of exoenzymes and then digests it with their hyphae. Because they do not need light for photosynthesis, they can live in any dark habitat, and grow in any direction. Their fruiting body used for reproduction is what we call mushrooms. Some scientists believe that molecular evidence leads to fungus being more closely related to animals then plants!

Because fungi feed on organic material, they are important in recycling nitrogen, carbon, and other nutrients. Some fungi are parasitic, feeding off of living materials and harming them in some way. Others live in beneficial relationships. Mycorrizae assist their host plants by helping the plant to capture water and elements from the soil such as zinc, phosphorus, and manganese, transferring them into the plant's roots. This fungi also protects trees against attack from pathogens. In return, the fungal partner receives from its host plant the vitamins, carbohydrates, and amino acids essential for its growth.

Fungi are much more than just the mold growing on our foods. They can break down almost every manufactured good except for some pesticides and plastics. They have been found to play a role in protecting plants in soils with high metal concentrations. They make fabulous bread and many other food products, including cheese. They are critical in antibiotics, steroids, and hormones. They even are the citric acid in our Cola! Finally, there are 250 species that are sought after food from the forest, while at the same time around the same number can be deadly or make you wish you were dead if you eat them. Mushrooms are certainly a part of our natural world that are “fun-guys” to have around.

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Fall Phenology

2010-09-14T08:27:00.000-07:00

By Susan Thurn,
CNHM Director of Education

What good is phenology? For some, it’s a year-round hobby that helps keep them in touch with the ebb and flow of the natural world. But the practice of noting and recording seasonal changes in nature does have what some would call more practical values.

For example, phenology is used to help with the prediction of insect emergence and strategies for insect control. Farmers, of course, are phenologists, and carefully correlate natural patterns and seasonal changes with crop planting and harvesting. Scientists who study global climate change trends pay close attention to the history of phenological data.

This time of year, the most obvious seasonal change is literally right in front of our eyes, as we are nearing the peak of leaf color change among our deciduous trees. The appearance of the beautiful yellows, reds, oranges we see is actually a result of the fading of the leaf’s green color, which is caused by cholorophyll. When chlorophyll fades, “beneath” it are other types of pigments that become revealed. These are the carotenoids, which produce yellow, orange, and brown colors; and the anthocyanins, which produce red, purple, and crimson colors.

The vibrancy of fall color is related to weather conditions that occur before and during the time when chlorophyll in the leaves is dwindling. A series of warm, sunny days and cool, crisp, but not freezing nights seems to bring about the most spectacular color displays.

The timing of the color change also varies by species. For example, oaks show their colors long after other species have already dropped their leaves. The differences in timing among species seems to be genetic, for a particular species at the same latitude will show the same coloration in high elevations at about the same time as it does in warmer lowlands.

Unique among the color-changing trees is the tamarack, also known as the eastern larch. In the spring and summer the tamarack has bright green flat, soft, and flexible needles. They are shaped uniquely on the branch in a whirled cluster somewhat like a flower’s petals. The trees are easy to identify by their narrow pyramid shape and their location—they’re most common in swamp and bog areas. This tree is both coniferous (produces cones) and deciduous (loses its leaves). Although the tamarack looks like an evergreen, it is not ever-green, because its needles change to a golden-yellow color in the fall and drop off.

About this time, northern flying squirrels begin visiting oak trees to feed on acorns. As the acorns mature you might find partly chewed ones on the ground. The squirrels feed at night, so if you want to see them, look for the acorns then keep your eyes open for squirrels scrambling up the trees.

Become a phenologist! Take a fall hike and note all the different colors of the forest. Gather wild apples and make your own applesauce or cider. Soak up the fleeting warmth of sunny fall days as we turn our thoughts to colder weather.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Moths

2010-09-07T08:36:00.000-07:00

An email from a Museum friend recently stated, “I was talking with a neighbor/friend of mine tonight about this weird bird/bug I saw in my hanging flower baskets last night. Further research proved it to be a white-lined sphinx moth! It looked so much like a hummingbird, but yet not...I just had to find out what it was.” Late summer often brings this sphinx moth around our flowers, and it can often be mistaken for a hummingbird. Another species that has similar characteristics is the hummingbird moth. Both are beautiful insects to be enjoyed this time of year as they flutter furiously about our flower gardens.

The white-lined sphinx moth has white streaks along its upper forewing and body, from which it gets its name. Adults fly mostly at dusk and dawn, but also sometimes during the day. Their wingspan can be as much as five inches, and with their rapidly beating wings, on a quick glance can be confused with hummingbirds. They feed on a large variety of flower nectar including fuchsia, bouncing bet, evening primrose, petunias and thistles.

The second hummingbird mimic is the hummingbird moth. It is much smaller than the white-lined sphinx moth, with an olive to yellow body coloring, red bands across the abdomen, and mostly clear wings. Their body really seems to mimic similar coloring as the hummingbird. These moths fly during the day, hovering at flowers as they sip nectar. Adults prefer a wide variety of flower nectar including bee balm, phlox, vetch, and thistles.

Both of these “hummingbird moths” are to be thanked for their contributions as pollinators. The caterpillars of both species are also very interesting to find and observe. It is worth some time waiting and watching for these two moth species as they travel into your own back yards.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Red-Tailed Hawks

2010-08-30T10:17:00.000-07:00

By Susan Thurn,
CNHM Director of Education

This was the week of the red-tailed hawk for me, as not only did I see them in flight, but I actually held one in my hands. The bird I held was a bird that can no longer live in the wild due to a dislocated shoulder. Just seeing this bird inspired awe inside of me. We often see red-tailed hawks soaring above open fields, circling while looking for their prey. Other times we may see them perched on a telephone pole. I would also guess that we all have heard the call of a red-tailed hawk, as Hollywood seems to have chosen the red-tailed hawk as the call on almost every movie!

Holding this red-tailed hawk in my arms was most amazing. The glove that protected my arm and provided the perch for the hawk just highlighted the amazing yellow coloring of their feet. Although it is one of the largest hawks in the United States, about 22 inches high and with a wingspan up to 52 inches, it only weighs about three pounds. The colors included a darker brown back, with paler brown below, a streaked chest, and a dark bar between its shoulder and wrist as seen from underneath. The red tail for which it is named is brick-red above and pinker below.

Red-tailed hawks will eat a variety of mammals that includes mice, voles, shrews, rabbits, snakes, and squirrels. They are capable of eating prey up to five pounds in weight. Red-tailed hawks have been observed hunting as pairs, each taking a side of a tree while trying to catch squirrels.

Very territorial, red-tailed hawks will aggressively pursue other hawks, eagles, or great-horned owls. Other behavior includes an elaborate courtship ritual in which the pair locks their talons together while in flight, spiraling down toward the ground before letting go. Their flight is a soaring, shallow v-shape called a dihedral, with very little wing flapping as they conserve energy. They occasionally hover above the ground while steadily beating their wings.

I was most impressed with the red-tailed hawk eyesight as this bird watched me like a hawk, responding to my every movement. Indeed their eyesight is thought to be 8 times better than that of a human. A red-tailed hawk can see a tiny mouse while flying 100 feet in the air! That is impressive, and makes it worth exploring red-tailed hawks from our own back yards.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

No-See-Ums

2010-08-23T11:05:00.000-07:00

By Susan Thurn,
CNHM Director of Education

“Ouch!” I exclaim. I look down to my arm ready to swat the mosquito I am sure just bit me. Yet nothing is there. Moments later, the itch begins, and the welt soon after is at least penny sized. These are the no-see-ums, a tiny biting fly that I hate to love. Aptly named, no-see-ums are less than ¼ inch long, a little black dots the size of a period that is very difficult to see. Boy, do we feel them though!
No-see-ums often stay in shrubs or the dead leaf litter across the ground. Just walking along can stir them up. They stay close to home, though, usually not flying more than about 350 feet from their breeding area. These flies, or midges, are just like many of the other flies or mosquitoes. They are active mostly at dawn and dusk. Only the females bite us. They need the protein in our blood to make their eggs. Yet how does such a small creature do this much “damage”? No-see-ums and other flies puncture the skin with mouthparts that look like scissor blades. Their tube-like mouth is called a proboscis, and is made up of several different parts. At the end of this mouth they have receptors to sense where to begin feeding. A pair of mandibles (the scissors) cuts the skin back and forth. Another part with backward facing teeth helps to move their mouth into their prey’s body. They then inject an anticoagulant saliva into our bodies, and finally begin to draw in blood from a blood vessel. These tiny creatures feed on mammals, birds, or reptiles. Males feed on nectar.

The no-see-um larvae hatch from eggs in water, mud, or moist leaf litter. The larvae eat dead plant or animal matter. During this part of their life cycle the larvae have a spiny “tail” that entomologists use to identify them. As adults, they have two wings with dense hairs that have special pigmentation that also allows biologists to identify them.

The reaction my body has is an allergic reaction to the proteins in no-see-um saliva. Thank goodness, for me, the itching subsides in a short time. In spite of my discomfort, these small insects do provide food to other creatures, making them just as important in the food chain. In tropical forests there is one species of biting midge that helps to pollinate chocolate, which helps in my mind to negate the irritation I sometimes have at their bites. Everything has its place, after all! For chocolate alone, perhaps it is worth loving them!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Where Have all the Monarchs Gone?

2010-08-16T10:55:00.000-07:00

By Susan Thurn,
CNHM Director of Education

Where have all the monarchs gone? Several Museum members have mentioned their concern that they have not been observing monarchs much this summer. Even my own searches have yielded only three caterpillars this entire season. I’ve seen only four or five adults. It is a dismal showing for one of my long-time favorite butterflies.

As adults, monarch butterflies are migratory creatures. They travel great distances each fall to spend winter in temperate climates. Despite the fact that the range of the Monarch’s summer home is quite expansive, the wintering grounds are very limited. Some of these butterflies travel more than 2,900 kilometers to spend winter in places such as Michoacan, Mexico. In the spring, they begin the migration north, lay their eggs, and it is their children that finish the migration to northern Wisconsin. This inter-generational migration is an amazing phenomenon. So why are the numbers of monarchs lower?

In 2002 and 2004, freezing weather in Mexico followed by heavy rains wiped out huge numbers of monarchs during those years, creating a decline in the population. Spring of 2009 brought hotter than normal conditions for monarchs migrating north again, which was followed by the one of the coldest summers since 1928 in much of the breeding area, and finally, poor conditions during the fall migration, resulting in a very small overwintering population This past February, severe hailstorms followed by 15 inches of rain in Mexico are thought to have destroyed as much as 50% of the already declining population.

Added to this problem is the ongoing issue of habitat destruction in the world of monarchs. With an increased use of genetically engineered crops to become herbicide resistant, it has become easier for farmers to spray weed killer, killing any weeds and surviving milkweed while not hurting the crops. Monarchs are also under threat in Mexico due to illegal logging at their overwintering sites.

Scientists believe it will take two or more years for the monarch population to bounce back. Even then, there are still these human factors nature provides that could be a danger to the future of monarchs. Conservation groups are encouraging us all to improve monarch habitats by planting milkweed in our gardens at home, and to encourage schools, farmers, or others with unused land to grow these beautiful perennials. Perhaps with these efforts we can continue to explore and wonder at monarchs from our own back yards.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Northern Flickers

2010-08-09T10:18:00.000-07:00

By Susan Thurn,
CNHM Director of Education

A whole host of flickers darted away from my vehicle as I drove down the road. The white rump and yellow tail feathers always make me smile. It is early August every year that the phenomenon occurs in which we observe flickers flying away from our vehicles as they leave the roadsides. It is perhaps a surprise to find a woodpecker being scared up from the ground rather than the trees, but northern flickers eat ants and beetles, digging for them with their unusual, slightly curved bill.

The northern flickers are foraging along roadsides mostly for ants. This bird species eats more ants than any other bird species in North America. Their long, barbed tongue laps up the insects off the ground. They hammer at the soil the same way other woodpeckers hammer into wood. By going underground they can eat the nutritious ant larvae as well. They also will eat flies, moths and butterflies, and in winter they add fruits and seeds to their diet.

Northern flickers have several interesting behaviors. The reason we see so many northern flickers this time of year is they are one of the few woodpeckers that migrate south for the winter. Also, unlike other woodpeckers, when flushed from the ground, flickers will choose thin horizontal branches to perch upon rather than tree trunks.

Northern flickers know their numbers. In spring and summer, rivals for a mate sometimes participate in a “fencing duel,” pointing their beaks up, bobbing their heads, and drawing a figure eight pattern in the air while calling their repeated “wicka” calls – all while the ladies look on.

Finally, flickers are known for their behavior called “anting” in which flickers allow ants to crawl up on their wings. There are different theories as to why this happens: one is that the ants’ formic acid is used as a fungicide or insecticide against feather or skin parasites or fungus. Another speculation is that anting is a comfort activity that stimulates the skin during a summer molt.

There are over 100 names for the northern flicker, including yellowhammer, gaffer woodpecker, wake-up, wick-up, and gawker bird. Not only do they have some fun names, but flickers are entertaining birds to watch. When we hear a drumming on a metal section of our house, it is often a flicker. When we see a feather on the ground with a yellow shaft, it is a flicker. How lucky we are to enjoy this bird species so often! Explore and wonder from your own back yard.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Turkey Vultures

2010-08-03T09:09:00.000-07:00

By Susan Thurn,
CNHM Director of Education

A dark silhouette was flying over the field, recognizable by its dark profile and v-shaped wings. It was circling, two days in a row near my home. I smiled when I recognized a turkey vulture. Was it circling for some carrion? Or riding the winds? Some may refer to this bird as ugly, but I think it is beautiful, and turkey vultures have behaviors and adaptations that make them extremely interesting.
The turkey vulture got its name from the common turkey because of the similarities to the turkey’s reddish, featherless head. This almost bald head covered with a fuzz of down serves an important purpose. The turkey vulture eats dead carrion, and must stick its head inside the carcass to reach the meat, so the lack of feathers keeps the bird clean of blood and bacteria.

The turkey vulture does not feed strictly on carrion. They will also eat plants, including shoreline vegetation and some crops. They will soar above the ground searching for their food with their sharp eyesight and very developed sense of smell. They are not aggressive, and will not feed on live prey. Sometimes we can see them along roadsides looking for roadkill.

Turkey vultures are one of the few birds that have a heightened sense of smell, and the part of their brain that processes smells is very large. This raised awareness allows them to detect odors of dead animals below the forest canopy.

Do vultures circle the air looking for carrion? Actually, turkey vultures soar on warm bubbles of air called thermals. As warm air rises, they glide in circles to conserve their energy. They also use the thermals to raise higher so they can fly longer distances. Flying in circles also serves the purpose of letting them scan for food. Vultures are easily distinguished as they maintain a v-shaped flight, teetering side to side, to keep stability at low altitudes. Flying lower to the ground in this shape allows them to pick up the scent of dead animals. This flight pattern is quite a remarkable skill in the bird world, allowing vultures to glide for up to six hours without flapping their wings, diving out of the thermals at almost 60 miles per hour.

Turkey vultures are related to storks rather than birds of prey, and so they urinate on their own legs, using evaporation of water in the waste to help them cool down. It is also believed that the urine is acidic, helping to kill bacteria they may get from stepping in their own dead food. Vultures also have weak, chicken-like feet, which allow them to step on the ground and hold their food in place, rather than like other raptors that clutch their talons and fly in the air with their prey.
There are some additional adaptations that turkey vultures have. They roost in large groups except when they forage independently. They often can be seen with their wings wide spread, called the “horaltic pose,” perhaps to dry their wings, warm their dark body in the sun, or bake off any bacteria. Although they do not have many predators, their defense is to vomit. They cough up a lump of partially digested food, and the smell deters predators, or if it gets in their eyes, stings. Sometimes, they will vomit a large amount of “meal,” which predators may choose to eat instead of pursuing the vulture.

Keep your eyes out for turkey vultures in the air nearby. They will begin migrating later in September, so will become even more visible. Who knows what you might see happen! Explore and wonder from your own back yard.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

The Lost Ladybug

2010-07-27T07:46:00.000-07:00

By Susan Thurn,
CNHM Director of Education

This week’s Museum Junior Naturalists went out in search of ladybugs. Ladybird beetles, to be precise. This adventure was part of a citizen science project for the Lost Ladybug Project, a search for native ladybugs organized by the Cornell University Department of Entomology. Twenty-six children ages 5-12 donned their insect nets in a field and forest edge along the Namekagon River. We swept above the flowers and plants with hopes of finding ladybugs. We placed a sheet underneath tree branches and gently knocked the branches to observe what fell out of the trees. After a thorough search, we successfully caught ONE ladybug, which promptly flew away. I had thought that an adventurous group of children would be the perfect eyes to spot a ladybug. Now I wonder if they even really knew what they were looking for. Do they, like I did as a child, play regularly with ladybugs?

How could it be that we could only find one ladybug? Three ladybug species, the two-spot, the nine-spot, and the transverse ladybugs were once common but now appear to be rare. Three other species, the parenthesis, spotted pink, and convergent ladybugs, are more common natives. Scientists believe these native ladybugs are disappearing, and the Lost Ladybug Project is using citizen-based science to help find them. Scientists are looking for information on which ladybugs are still present and how many individuals can be found.

While many of the natives seem to be disappearing, ladybugs from other places have greatly increased their numbers and range. Many of us are familiar with the multicolored Asian ladybug, introduced from Japan for biological control of insects. This ladybug has a big appetite, and has adapted to eat the same foods our native ladybugs eat, even eating native and its own ladybug larvae. This is the same ladybug we see in our homes as they winter in huge masses. The checkerspot and seven-spotted ladybug are also ladybugs that were introduced into North America in the late 50’s and 60’s, and their populations continue to spread.

What are the current results of the Lost Ladybug studies? According to the ladybugs being reported, the numbers of introduced ladybugs far exceeds that of the natives. Over half of the findings are introduced ladybug species. Scientists are discovering which habitat niches in which the native ladybugs are the most successful. They are finding that the Asian ladybug is spreading its range into places that wasn’t previously inhabited. Pathogens are being found in native ladybug populations which could be contributing to their decline. Research is showing that native ladybugs that have less food grow into smaller, shrinking adults. Finally, evidence is appearing that the native nine-spot is inter-breeding with the introduced seven-spot ladybug.

Why should we care about ladybugs? They are beautiful. I remember as a child of seven, loving them, catching them again and again and enjoying their tickles across my skin. I learned from a ladybug about how animals use their bright coloring as a warning to predators to remind them of the awful repellents they release when attacked. They are very important because they assist with eating other plant-feeding insects, keeping those populations low. The fewer the ladybugs, the more fragile ecosystems can become during a pest insect population explosion. Keep your eyes open for a ladybug in your own yard. Share your ladybug stories at the Museum’s Nature Watch blog at www.cablemuseumnaturewatch.blogspot.com. Explore and wonder from your own back yard.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Night Sky

2010-07-19T07:35:00.000-07:00

By Susan Thurn,
CNHM Director of Education

The “dog days” of summer are here! We refer to them as the hottest days of the year. These dog days are based on an ancient Greek belief that Sirius, also called the Dog Star, was responsible for the heat. Skywatchers of long ago actually thought that the heat from Sirius and the sun combined to produce hotter weather. Ancient Egyptians used the star as a “watchdog,” as Sirius appeared in the night sky right before the Nile River’s flooding season. There are several interesting events to watch for in the next week in the night sky as we enter this year’s dog days.

Right after sunset, be sure to check out the low western horizon to see the planets lined up, from left to right, Saturn, Mars, and Venus. Venus is so bright it is the second brightest object in the sky (next to the moon,) so look there first. Mars and Saturn are next to it, but they might be fainter. Each night, they seem to be getting closer and closer together, which is a line of sight effect, but still a fun race to watch in the night sky. A glimpse of Mercury can also be made down very low in the skyline, but a pair of binoculars might help to view it.

There are exciting stars and constellations to look for in our night sky. Look south in the night sky for a bright orange star called Antares that helps to identify the hook-shaped Scorpius, while just to the left, the brightest stars of Sagittarius form a teapot. The steam above the teapot’s spout is the Milky Way. Look in the eastern sky for the summer triangle. The brightest star shining in that direction is Vega. Deneb is the star on the lower left corner of the triangle and Altair is on its lower right.

The last night sky treats to watch for include the July 26 full moon, and the southern Delta Aquarids meteor shower peak that will occur July 28-29, producing 20 meteors per hour at their best. The best viewing of this meteor shower is in the east, after midnight, in the constellation Aquarius. Jupiter also begins rising in the east between 11:00 p.m. and midnight, and for those who are early risers, the brightest object in the southeast before dawn, is Jupiter.

Turn out the night lights in your home, and get outdoors with a telescope, binoculars, and a chair or blanket. Explore and wonder from your own back yard.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Woodland Butterflies

2010-07-13T07:20:00.000-07:00

Woodland Delights

Susan Thurn,
CNHM Director of Education

My mother is a passionate gardener, and she knows all of her plant friends by name. Others have birds at their feeder, or squirrels, chipmunks, or bears that they know and call by name. A Museum member called to report her repeated observation of Compton’s tortoiseshell butterflies this week. The following day, I was out scouting Mount Telemark for a hike up the big hill, and saw a variety of woodland butterflies as well. In northern Wisconsin, we have several woodland butterflies that are worth getting to know by name. Please let me introduce you to the Compton tortoiseshell, northern pearly-eye, common wood nymph, and little wood-satyr, all woodland delights.

The Compton tortoiseshell butterfly is more common in our northern counties. It belongs in a group of butterflies called true brush-foots because they appear to have only four legs. Their front forelegs are reduced in size, usually hairy and resembling brushes. Adults emerge in July, in deciduous woodlands, trails, openings, and woodland edges. From above, this butterfly looks mostly a rusty orange and black butterfly, with single white marks near the edge of each wing. The wings have sharper angles with a small tail on the hind or lower wing. From below, the butterfly could be mistaken for tree bark, as they have a camouflaged coloring with a silvery mark in the middle of the hind wing. Last year, Compton’s tortoiseshell butterflies were seen in higher numbers, as the species does have periodic fluctuations in its populations, being abundant for years and then disappearing for other years. Its common name is from a famous English naturalist, Philip Gosse, who studied the butterfly while living in the town of Compton in Quebec in the nineteenth century. These butterflies overwinter as an adult, mating in the spring for a July emergence.

The northern pearly-eye butterfly is a common woodland species rarely found in openings. It is also commonly seen in woodlands, woodland edges, or while we are hiking down a woodland trail. This species is best identified by its brown coloring with lighter areas on the fore or front wing, and two obvious dark spots through both wings. Other spots trail down the hind wing. From below, the spots are circled with a yellow, brown, and white ring. The hind wing spots have a small white dot in the center. This species may be more difficult to identify with its fast, erratic flight that sometime ends further away against a sunlit tree.

The common wood nymph may be the most common butterfly in Wisconsin in a woodland habitat. Its lack of color makes it less conspicuous, but still worth looking for. This species is usually seen from below, so its underside has two large eyespots with a yellow ring on its fore wing. It is most often found in open fields near woodlands. This is the most common satyr butterfly that can be seen, and the best time to catch a flash of this butterfly is in July.

The less common little wood-satyr is often mistaken for a northern pearly-eye, but the little wood is much smaller, and found flying within only a few feet of the ground. They also fly more slowly, looking almost lazy in its flight. From above, it has two obvious eyespots on the fore wing and on the hind wing, ringed with white. When seen from below, it has two eyespots on the fore wing, while the hind wing has two eyespots and several smaller eyespots. There are also two darker lines across both wings. This species is also found earlier in the season, more in June than July.

My passion in nature is for butterflies. I try to know all their names, and take great joy in learning more about them through observation. These four butterfly species are all so amazingly camouflaged that I find it difficult sometimes to identify them. I use little things to help me remember them: Compton’s – orange and black with white; pearly-eyed – two main spots, trailing spots, with white dots in the center; common wood nymph – obvious large eyespots on the forewing with yellow rings; little wood satyr – smaller with two spots on top (forewing) and two on bottom, and lazy flight near the ground. May you all get to know these butterflies, and enjoy these woodland delights!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Eggs in a Basket

2010-07-06T09:02:00.000-07:00

Susan Thurn,
CNHM Director of Education

The Eastern phoebe is nesting in the same nest again in my house eaves. Not just for the second year, but for the second time this year. Many bird species have more than one brood in a season. Birds may lay more than one brood per year as a survival strategy. A bird is driven to pass on its genetic material through reproduction, and more young can mean more of them reach adulthood. Many songbirds have enough time to raise more than one family with a short period of time between egg-laying and fledge time. Their young can still have time enough to fatten up for their southern migration, or to prepare for our northern winters. It used to be thought that most birds nested for life. However, some birds do not nest for life, and some birds do not even keep the same mate for a second brood. How many eggs does a bird “put in a basket,” anyway?

Eastern phoebes are very loyal to their nesting locations, using them not only for their typical two broods per season, but also using them for many years. The phoebe makes repairs to the nest, apparently following the 3-R’s – reduce, reuse, recycle, by using the nest again. Most research suggests that phoebes keep the same mate through the season. Other birds in our region that can have two broods per season with the same mate include chipping, field, and song sparrows, juncos, towhees, catbirds, and robins.

Birds that often have two broods per season and sometimes choose different mates for the second brood include brown thrashers, bluebirds, and house wrens. The story gets even more interesting, however. Bluebird studies have shown that generally, northern birds have fewer broods than southern birds, but still have about the same number of young each season. In our neck of the woods (or fields, as that is the habitat bluebirds prefer,) bluebirds have two broods. Further south, where the food supply of insects is greater because of a longer warm season, bluebirds have three broods. Broods in the north lay more eggs than bluebirds in the south, and so end up with about the same number of young.

Would it be better to have more babies at once, or spread them out over one season? Would there be an advantage to having more nests, but fewer mouths to feed? Do northern birds sacrifice time to raise and train fledglings? Perhaps only a parent could know. Actually, it appears that there is a trade-off because although southern birds might have a “basket” full of more eggs, they have higher hatching failures.

It is fascinating to continue discovering about the natural history and science of birds. It was a Museum member who brought this question about birds and their second broods to my attention. It is often this spark of curiosity that will lead us to our own discoveries, perhaps to a bird in our own neighborhood that is in the midst of its second brood.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Weather Folklore

2010-06-28T10:28:00.000-07:00

Susan Thurn,
CNHM Director of Education

“Wait a day and the weather will change.” Although a common saying in northern Wisconsin, it hasn’t been true lately. Although we have been the lucky recipients of some long-awaited, much-needed rain, cabin fever is setting in to my brain. Also, with several education programs at the Museum this past week, I’ve been looking upwards a lot to find out if we are doing outdoor or indoor explorations, I also have been interested in how to tell if it’s going to rain, and interested in how people can know this without going to the local television forecast, or the Doppler radar on the internet. People have been forecasting the weather for centuries. They have looked to plants and animals – are ants moving to higher ground, do the frogs croak more frequently, is a sheep’s’ wool uncurled? Are there signs we can use to tell us if it is soon going to rain?

First, I go to the Museum’s Naturalist, Cully Shelton, as he always seems to know when it’s going to rain in the next few minutes. Cully recently told me, “When the clouds seem so low you could touch them…when the clouds are touching the trees, then it’s likely that there is going to moisture precipitating out of them in a short length of time. Another favorite observation I use is when you see puffy, white cumulus clouds, which means that within a 12 hour period there should be rainfall.”
What about some of the folklore we all know? "When the glass is low on a ship, the sailors get ready for a storm,” or "When your joints hurt, a storm is coming," are common occurrences we often hear. Both of these folklore statements refer to low air pressure systems which do often mean storms are on their way.

"Red Sky at night, sailor's delight. Red sky in the morning, sailor take warning." It turns out there is some truth to this saying. When our western sky is clear, we often get a red sunset because as the sun sets, its light shines through the lower atmosphere containing more dust, smoke, or pollution. With these clear skies and high air pressure, the air sinks, causing the contaminants to be held closer to the earth surface. These particles scatter the shorter wavelengths of light, leaving longer wavelengths that create orange and red colors, creating the sky that brings weather delight to the sailor. If the sky is red in the morning eastern sky, the high pressure may have already passed, and a low pressure period may follow, usually bringing clouds, rain and storms.

Another favorite folklore statement is, "Mare's tails and mackerel scales make tall ships take in their sails." These mackerel fish scale looking clouds make reference to cirrocumulus clouds, and mare’s tails represent cirrus clouds. Both types of clouds can indicate a warm front that is approaching where two air masses meet, bringing changing winds and precipitation. This prediction of high winds would make it necessary for boats to reef their sails.

"When the stars begin to huddle, the earth will soon become a puddle" is another clue that can be used to forecast weather. As clouds increase, large areas of stars are hidden, while a burst of stars can seem to be huddled together in a section of clear sky. As this sign means the clouds are increasing, the chance of rain is definitely possible.

There are also some clues we can also learn from nature. Some flowers close up as humidity levels rise so their pollen doesn’t get washed away. Cicadas cannot vibrate their wings in high humidity, so can be silent with approaching rain. Swallows sometimes fly lower when there is dropping air pressure. Crows and geese have been known to call more frequently with falling air pressure. Flying insects are more active when air pressure is dropping, staying closer to the ground so that it might seem like they are swarming. With all of these clues, who needs a television or computer?

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Clean Air

2010-06-22T06:55:00.000-07:00

Susan Thurn,
CNHM Director of Education

Breath Deep

Take a deep breath. And again. I just spent a week’s honeymoon in New York City, and I learned one incredibly important thing this past week. I love New York, but I love clean air even better. I learned how much I take our northern Wisconsin’s clean air for granted. The cultural and architectural sights, the Broadway shows, the food, and the 10 million working people of New York City were all amazing, but I missed the air of the north woods. I missed waking up and knowing the weather outside, sunny or cloudy, without having to try and figure it out through the smog. It was a fresh breath of air coming home again!

Air – we breathe and expose our lungs to about 35 pounds of it every day and 2 gallons every minute. This air is made up of gases – nitrogen, oxygen, argon and other natural ingredients. Smaller amounts other naturally occurring gases are found on earth such as water vapor, carbon dioxide, methane, nitrogen dioxide and sulfur dioxide. Tiny particles, bits of earth, sea salts, pollen, and microscopic microbes, are blown into the air. These substances play an important role in regulating and sustaining life on our planet.

According to a New York City Community Air Survey, wintertime air quality across the city, found results that Manhattan and the more developed, high-traffic locations in five of the studied boroughs have the city's highest particulate levels. The beautiful Manhattan skyline has certainly been changed by the smog and air particulates. This is just one part of our planet, however. According to the Environmental Protection Agency (EPA,) 50 million Americans live with ozone levels above the current national standard. Worldwide, 1.4 billion people breathe polluted air every day.

None of this information about our air is a surprise to us, and there is good news. According to EPA estimates, the Clean Air Act has helped significantly through a savings of $22 billion in health costs, material damage, and more. Here at home in northwestern Wisconsin, we have an air quality index that is marked as “Good.” In comparison to other places, perhaps it should be marked excellent.

In spite of this good news, my recent city experience was a strong reminder of what daily life could be like in other places. Wisconsin, like all other states and countries fights their battles with growing carbon dioxide emissions, ozone, mercury, and a host of other air quality issues. This past week brought about a renewed sense of commitment to decreasing my personal global footprint. Let us all be reminded of the air that we breathe daily and all take for granted. Let us stop what we are all doing for a moment, breathe, and appreciate what we take in every day, every moment of our north woods lives, and enjoy it!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Turtle Crossing

2010-06-14T07:38:00.000-07:00

Susan Thurn,
CNHM Director of Education

Beware! It’s turtle crossing time! Over the weekend, I was saddened to find a 20+ year-old snapping turtle dead on the side of the road. Phone call questions have also come into the Museum asking about turtles and how to cope with their change in lifestyle that impacts ours this time of year. Motorists are likely to see turtles crossing roads near lakes, rivers and wetlands right now because the roads separate the aquatic habitat, from the drier soils in upland habitats that female turtles prefer for egg-laying. Their nests also end up in our backyards and driveways, making for an exciting experience!

All Wisconsin turtles lay their eggs on land, usually in a nest that they dig. Painted turtles may nest twice in the same season, but other species only once. Most turtle species begin their nesting around dusk or dawn, although it can occur throughout the day. Snapping turtles can lay 30-80 eggs, while smaller turtles lay up to five eggs. Once the eggs are laid, the female departs, allowing the eggs to hatch on their own. There is great danger in making a roadside nest. The mortality from automobiles is significant because turtles are very slow to mature, taking up to 20 years to reach sexual maturity. This makes it important for motorists to drive with caution in wetland areas in order to protect our female turtles.

Although the danger is over once the female adult turtles have left the nest, the danger has just begun for the eggs. Turtle eggs can take 60-90 days to incubate, and so are often uncovered and eaten by predators such as raccoons, foxes, skunks and crows. With cooler summer temperatures incubation can take longer. Turtles that hatch in the fall overwinter in the nest, using a glycol/sugar antifreeze to keep the eggs or hatchlings from freezing. Summer temperatures actually determine the sex of many Wisconsin turtles. Blanding’s, painted, box, and snapping turtles produce more females at higher temperatures, while more males are produced at lower temperatures.

For those who might find a turtle who has laid eggs in their yards or driveways, and are looking for a way to protect the nest from their pets, or predators, resources suggest placing an object over the nest site such as a oven shelf or plastic egg crate that might prevent predators from digging to get the eggs. This past week’s rain might also help erase the scent that many turtles leave behind, making it more difficult for predators to smell the eggs.

Help a turtle by allowing them time to cross roads, while keeping safety in mind. Road mortality is especially significant for our rare and endangered Blanding’s and wood turtles. However, even our more common snappers or painted turtles can experience mortality rates that cause populations to decline and suffer. Almost half of Wisconsin’s turtles are experiencing declines. Giving turtles the time to move out of the way or occasionally using a stick to help them move to safety can truly help an animal that is a fascinating part of a diverse northern Wisconsin.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Whip-Poor-Whil

2010-06-08T07:03:00.000-07:00

Susan Thurn,
CNHM Director of Education

It is a bird I have never seen, but hear every night right now, just outside the windows of our house. The song goes on for what seems like forever. It is the sound of a whip-poor-whil, singing “whip-poor-will” with an accent on the first and last syllables. A famous naturalist, John Burroughs, once heard a whip-poor-will make 1,088 vocal repetitions before taking a break. Whip-poor-wills belong to a family of birds called nightjars because their loud songs "jar" the night. They are also called goatsuckers because of a superstition that the birds drink milk from farm livestock at night. The name whip-poor-will and that of many other nightjars is a fairly accurate description of what the bird sings.

The whip-poor-will song begins in the spring. During their courtship, the female will land near a calling male, who then will walk towards her with a fancy gait, head bobbing up and down. When he reaches her, he circles as she bobs, while both continue to sing their songs. He will also approach her from the side and touch her bill while she trembles. The nest is built on the ground on leaf litter in areas where there is little or no undercover. The birds time their egg-laying with the moon, synchronizing it so the usual two eggs hatch about ten days before the full moon. This timing allows the adults to forage all night for food with the greatest amount of moonlight. Both parents feed their young regurgitated food. The chicks hop along the ground very quickly after hatching, using their parents camouflage to hide them. If this fails, the young scatter and freeze while the adults distract the invaders. How unfortunate that we rarely get to observe any of these activities!
Hunting is obviously a part of the whip-poor-whil’s nocturnal lifestyle, and while an owl hunts mostly by sound, the whip-poor-will searches for its prey by sight. As a result, they are most active at twilight, dawn, and on brighter moonlit nights. They will catch insects, ranging from mosquitoes to moths, grasshoppers and beetles. In spite of a small bill, they can open their mouths wide when in flight, foraging while wheeling or circling, even hovering for their prey. They will also make short flights out from the ground or branches to catch prey. They use the silhouette of their prey against the night sky. Such creative strategies for hunting!

Legends of whip-poor-whils include a New England story that the bird can sense a soul departing, and can catch it as it flees. An American belief is that the singing of the birds is a death omen. Stephen King and other movie creators have used the song to help create suspense or other moods.

How can a human be lucky enough to spot a whip-poor-will? Their eyeshine reflects red at night, and sometimes they can be seen in a moth-like flight. The birds can sometimes be seen sitting on roads, with small, weak feet and short legs, as they hop about awkwardly. They usually sit lengthwise on their perch instead of other birds who sit across them. Perhaps someday I will be lucky enough to capture a visual moment of a whip-poor-will. Until then, I will enjoy, as do my neighbors, their nightly song.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Nest Sanitation

2010-06-02T07:42:00.000-07:00

By Susan Thurn,
CNHM Director of Education

A pair of tree swallows has built their nest in the Museum’s bluebird nesting box. The Eastern phoebe is back again on the same nest at my house. The bald eagle is back roosting on the same tree on the Namekagon River, not far from its nest. Imagine the fragility of a nest, which often forces birds to build a new nest every year. However, nests that overwinter can harbor deadly numbers of pathogens or parasites that await the returning birds. What do birds do to cope with these issues?

Nests are often alive with invertebrates that feed on birds, their waste, or on each other. Flies, ticks, mites, fleas, and ticks or bacteria and fungi are discouraged by many different strategies birds use.

One of the most widely used methods is to remove the fecal sacs of the young. Some materials are selected by the parenting birds that help to sanitize the nest. For example, some hawk species continually add fresh leaves that contain pesticides such as hydrocyanic acid, which impacts parasites. Starlings can discriminate between leaves and choose the best to deter lice or bacteria which they include in their nests. Cedar bark is also used for its repellent properties. Nuthatches rub pine pitch and insects around the entrance to their cavity, relying on the defensive chemicals of the pitch and insects to protect them. Some birds of prey’s young defecate outside of the nest or in other birds, outside their nest hole opening. Some bird species put carnivore scat in their nests to repel smaller predators. The great-crested flycatcher puts a snake skin into its nest, which is believed to deter predators such as squirrels.

Birds definitely go to great lengths to protect their young. If heavy parasitism or infestation of a nest begins, birds will desert the nest, and in some cases, entire bird colonies have moved themselves to a new site. It is amazing the ingenuity that the bird world uses to survive!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Spring Azure

2010-05-24T09:50:00.000-07:00

By Susan Benson,
CNHM Director of Education

A small flash of blue flutters by on a bright sunny day. This is the spring azure butterfly, which although cannot have the title as first butterfly we see, it is the first butterfly to emerge from its over-wintering chrysalis. I have been observing them for a few weeks now, although late April is usually the earliest we see the adults. When I see my first blooming violet, I know to begin looking for these tiny, one-inch blues. Where can we best find a spring azure butterfly? Woodland edges, bogs, swamps, overgrown fields, and pine barrens are some of their preferred habitats.

The small spring azure caterpillars are light green with a darker-looking green stripe along their back. They feed on the leaves and flowers of dogwood, cherry, and blueberries. They have an amazing symbiotic relationship with ants, producing honeydew, a sweet substance that attracts ants. The ants feed on the honeydew and protect the caterpillars from predation until they form their chrysalis.

This butterfly has only one brood per summer, making our observations of them that much more special. The females only live for about four days, mating on the first day and laying their eggs on day two. The adults seldom eat nectar or other foods with such a short life cycle.

Looking in a dictionary, we can find definitions of the word azure such as: of or having a light, purplish shade of blue, like that of a clear and unclouded sky. Certainly this butterfly species is aptly named, and thoroughly enjoyed!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Warbler Migration

2010-05-17T07:16:00.000-07:00

By Susan Benson,
CNHM Director of Education

May is the best time for seeing some of the most beautiful birds, the warblers. These small birds are on their way back from Central and South America, nearing the completion of their thousand mile or more journey to their northern breeding grounds. These mostly insectivorous insects are nocturnal migrants, flying almost non-stop trips, or stopping for several days along the route to refuel their bodies for the next flight. Warblers fly in flock or waves, bringing a bright spot of color to our lives. Many male warblers also sing their beautiful songs, making them even more noticeable. On a good day after a warbler wave has arrived, a birder can see or hear over a dozen species of warblers. Here are some special warblers to keep an eye or ear out for:

Yellow-rumped Warbler: Named after its most distinctive yellow patch above its tail, this is a commonly seen warbler in spring. The brighter males forage higher in the trees than most other warblers. They are also the warbler that is most likely seen darting out from a tree to catch an insect. Their preferred habitat includes mature coniferous and mixed coniferous-deciduous woodlands. Their song is a variable trill.

Black-and-white Warbler: With its distinctive black and white plumage, it forages for insects while creeping along the trunks and branches of trees like a nuthatch. It is one of the earliest migrating warblers and prefers mature or second-growth deciduous or mixed forests. Its sweet sound is a “wheezy, wheezy, wheezy, wheezy”

Black-throated Green Warbler: As its name suggests, the male has a black throat, and is also noticeable with its yellow face. This bird is often heard rather than seen, as it prefers conifer trees, and usually is hiding deep within one. Its "zee zee zee zoo zee" song is very distinctive, and as this bird chooses to stop for its breeding season in northern Wisconsin, we continue to hear it throughout May into very early June.

These are just three of maybe fifteen easier seen or heard warblers in the north woods. Look for warblers near you by finding their preferred habitats. Forest edges and near waterways are also good places to look or listen for warblers. It is also worthwhile to listen to a bird songs CD to learn more about warbler song identification. Grab your binoculars and your field guide to enjoy the color and song show!

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Black Bears in Spring

2010-05-11T07:11:00.000-07:00

By Susan Benson,
CNHM Director of Education

With snow falling on the ground it was difficult to write about a spring phenological observation. This morning when I awoke to several inches of snow on the ground, I discovered a thief that had been by the house during the night. My fiance has a 1974 Classic Plymouth Duster, a very nice looking car. Having just taken it out of winter storage, he had covered it with a rather pricey car cover. This morning the car cover was gone, completely out of sight. Upon much inspection, we discovered the culprit – a black bear. It would have been unbelievable had I not seen the bear tracks with my very own eyes. Or have seen the tooth or claw marks in the car cover. What could that black bear have wanted with a car cover? Good protection from the snow, the very thing we were protecting the car from? Food? My theory is that this made in China car cover perhaps was made using “waterproof” fish oil, and the bear caught the scent and was hoping for a fish meal. I guess we’ll never know what was in this bear’s mind, but it made for a very comical morning. What do bears eat in the spring, anyway?

When black bears emerge from their dens in mid-March, they recover near the den as their metabolism revs up again. During this time their fur looks healthy, but soon they shed their winter coat. When their digestive system is ready to go, black bears will begin foraging to replace lost calories from the long winter without food. Bears, especially the males, will travel long distances in the spring to find food. Males home range can be fifteen to twenty-seven square miles, while females usually maintain a five-square mile area. If food is scarce, bears will wander farther from their territory looking for food, and may extend their feeding hours into the daylight. In mid-May, the breeding season begins, and the males will start roaming greater distances.

If a sow gives birth during January or February, her cubs will stay with her 18-24 months. She communicates with her cubs using her voice that includes “woof” and whimpering sounds.

Black bears locate their food by relying on their amazing sense of smell. A black bear can smell a candy bar from two miles away. They feed mostly from evening twilight until sunrise. In early spring when plants are still dormant, bears will rely on small mammals or carrion for their food. They will also rip open rotten logs or anthills to feed on the insects, both eggs and larvae that are found inside. As plants begin to sprout, black bears will switch to up to 40 different types of plants. They will also eat last year’s berry crop, tubers, acorns, nuts, mice, squirrels, or beetles. Bears molars are flattened for grinding and chewing plant food instead of slicing through meat.

Missing car covers, tracks in the snow, or disappearing bird feeders are not the only signs to look for of bears. Their scat filled with digested plants or seeds is very noticeable. Even as I write this, I continue to ponder and smile at our morning visitor, wondering just what it wanted with the car cover. Please send your own black bear stories to info@cablemuseum.org, or post a comment on the Museum’s Nature Watch blog, cablemuseumnaturewatch.blogspot.com.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs.

Green Darner

2010-05-03T12:26:00.000-07:00

By Susan Benson,
CNHM Director of Education

This past week I was bitten by a dragonfly. It was April 27, to be exact. I hope no one gets too alarmed by this statement. Dragonflies are not exactly one of the animal world in which we fear. This event, however, goes down in my phenology journal. I have always had a close relationship with insects, as I have been an avid fan since I was in second grade. I could share the most inane details about certain insects that would bore people in minutes. Dragonflies land on me, or near me, regularly when I am near water. I have always thought we were big buddies. As my fiancé and I were walking down to the Namekagon river, he asked me if dragonflies bit, and I promptly answered, “they could, but they never would.” I was in the midst of rescuing a damaged, but beautiful specimen. Just as I was ready to put it down, it bit me, again and again! For a moment, I felt great sympathy for mosquitoes.

This dragonfly was a green darner, easily identified by their green thorax and bright blue abdomen. They also have an obvious bull’s eye pattern on top of their face. Green darners are the first dragonfly to be seen in early spring, and their second “flight” begins in early August through October. In the fall, northern juveniles migrate south, flocking together in the thousands. They fly south to the southern states, and their offspring fly north in the spring. They arrive in our region, lay eggs, and those eggs become the juveniles that leave us this fall. Local birders believe that the green darner migration occurs at the same time the American kestrel migration happens down the North Shore, and it is believed that the kestrels feed on the green darners as a migratory fuel source. It is possible that we have a non-migratory population as well. These residents overwinter as nymphs and hatch in the spring.

Green darner eggs are laid inside stems of aquatic plants. The female uses her sharp, egg-laying ovipositor to pierce the plants. It is during this egg-laying time that females must beware or they may become dinner to a fish. The hatching darner nymphs, which to me look almost “alien,” live in the water and feed primarily on fish eggs, tadpoles and aquatic insects. Adults eat fly midges, mosquitoes, caddisflies, butterflies and moths, and other flying insects. In general, this species prefers fishless habitats that have still waters such as permanent or temporary ponds, marshes, or slow streams with emergent vegetation.

Green darners are nicknamed because their abdomen looks like a darning needle. They are also called mosquito hawks. With their outstanding flight abilities and almost 360-degree sight, they can fly fifty miles per hour and kill prey larger than themselves. They can also reach altitudes of nearly 18,000 feet. Scientists track their movements through tiny locating beacons which allow us to know so much about these species.

I could impress everyone with my knowledge that dragonflies belong to the order Odonata. A translation of this word is “toothed ones,” due to the awesome lower lip, which used to capture and hold their prey while their mandibles do the eating. Indeed, I now know all about their mouth parts, and have the two millimeter “owie” to prove it, along with a whole new dose of respect and admiration for these insects.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Woodcock Sky Dance

2010-04-26T07:23:00.000-07:00

By Susan Benson,
CNHM Director of Education

It was later in the evening, about a week ago that I was out hooting for a barred owl response. Lately, the barred owls have been frustratingly elusive. However, this particular evening, I heard a sound of another bird that was exciting to hear. The American woodcock was “peenting.” “It was doing what,” you say? Some look funny at me when I say the word. No, “peenting” is not a dirty word. Peenting is sound made by the woodcock during its elaborate courtship display that the male uses to attract females. What a show the male woodcocks provide!

First, the woodcock begins his song and dance at sunset, in a field or clearing. He sings out, calling repeated “peents,” followed by an occasional bobbing or curtsy of his head, a turn, and a repeat of the dance again while broadcasting his song in different directions. After a few bobs and peents, he flies upward into the sky in a wide spiral, moving higher and higher. As he gets higher, his wings whistle, creating a “twittering” sound. How is the twitter made? As air passes between the first primary feathers on his wing, it produces a whistling sound. As the woodcock gets to a height of 200-300 feet, he begins to chirp. The vocal chirping sound marks the descent downward, where he spirals or zig-zags back and forth, diving quickly down to the ground without a sound. Just as the chirping stops is when a look just above the horizon can show him flying in for a landing. When he lands, he often settles in at almost the exact same spot, with hopes that a female is nearby. Then he starts the entire dance again. The display goes on sometimes for at least an hour past sunset, or on moonlit nights, even longer.

The male American Woodcock does not provide care for its young, but continues the display even after females have laid their eggs. Some males will use different song and dance grounds, mating with several females.

It was Aldo Leopold who named the woodcock spring rituals the Sky Dance, as anyone can read in his Sand County Almanac. I learned first about the song and dance while waiting for its flight dance. Once it left off into the air, I would sneak up closer until I was just a few feet away in the dusk light. I watched with delight as it sang and danced. There is magic in experiencing the woodcock dance, and is a spring ritual not just for the woodcock, but for birders like me to enjoy. Try it on your own some night soon. Seat yourself under a bush just off the dance floor and wait, watching against the sunset for the woodcock’s arrival. Once finished watching the display, then curl up on the couch with a copy of Leopold’s book to relive the magic once again.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Migration

2010-04-23T06:41:00.000-07:00

By Susan Benson,
CNHM Director of Education

What causes the push for bird migration? With an early spring, do the birds return early? Food and reproduction are the two most critical factors in migration. The changing seasons cause decreases in a bird’s food supply, causing birds to move to an area with more plentiful food availability. With a greater density of birds in the southern areas during our winters, food supply gets shorter, causing a push to move to another area where greater food supplies exist. A second factor is that birds also migrate to an area to raise their young. What are the internal and external cues that lead to this bi-annual migration for so many birds?

A major cue for bird migration is the change in day length, or photoperiod. These changes cause different hormone levels in birds that affect metabolism and the drive to reproduce. As daylight lengthens, there is a change in the lower part of the brain, the hypothalamus, that controls hunger and causes birds to gain weight through overeating, leading to as much as a forty percent weight gain. These fat deposits are stored in the bird’s flight muscles, under their skin, and in their abdominal area. Birds maintain this weight gain metabolism throughout their migratory activity. As daylight changes, other hormonal changes in birds lead to a display of higher activity, or restlessness in birds, especially at night.

Hormonal changes also bring a drive for reproduction. Spring migration becomes an urgent time for birds, as there is an optimal time for birds to arrive in their breeding areas. Stronger males arrive first to stake out the best nesting habitats. When females arrive, they select the prime areas in which to raise their young. For example, the house wren males arrive first into the northwoods habitats. They will begin building up to twelve different nest sites. Although they weight the equivalent of two quarters, the males will harass other larger birds, even taking eggs or young out of a nest site they want. When the female arrives, she chooses what she believes will be the most successful nest, and that male becomes her mate. Younger males will learn from their elders, usually choosing to nest near the older males, gaining knowledge of the best nesting habitats.

It is believed that day length is not the only factor that stimulates the drive to migrate. Temperature also plays a part. When spring is late, birds do not arrive early, and when spring is early, the birds can move in earlier to take advantage of the best natural resources. Scientists also believe that vegetative cover can influence light levels to impact reproduction.

Although there can be variability from year to year, scientists do believe that long-term averages show a trend that, in the last 20 years, birds are arriving earlier, and a larger number of species are shifting farther north in search of food. The theory is that climate change could be disrupting some birds’ migratory patterns.

Is there any time better than spring (besides, summer, autumn, and winter, of course?) Right now, spring rules our world, bringing us opportunities for observing birds in their bright plumage, or outdoor concerts as the males sing, declaring their territory. Spring is so sweet!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

What dates have the American robins return? The following dates were reported by Museum members:

1995 3/16

1996 3/21

1997 3/21

1998 3/23

1999 3/11

2000 3/15

2001 3/18

2002 3/26

2003 3/26

2004 3/22

2005 3/22

2007 3/21

2009 3/15

2010 3/18

Salamanders

2010-04-12T10:28:00.000-07:00

By Susan Benson,
CNHM Director of Education

With the forecast of a possible rain, it is difficult not to get excited, since it seems like a long time since we have seen precipitation in our area. One of the events I will be looking forward to is an event that happens yearly after the ground has thawed and the weather warms up. Salamanders are often on the move during the first warm, hard, night rain. Salamanders are amphibians not as well known as the spring peepers or other frogs because they are very secretive. In order to see one, it helps to be outdoors at night, as they are a mostly nocturnal animal. In Wisconsin, we have seven species of salamanders, whose cold-blooded body temperatures reflect their environments. They prefer night as they can take advantage of cooler, more humid conditions that keep their skin from drying out. They are most easily seen in spring and fall as they migrate to and from their breeding wetlands. With enticing names like newts, mole salamanders, lungless salamanders or mudpuppies, who could not want to learn more?

Where are salamanders in the spring? As soon as the edge of the ice is open, salamanders move from their terrestrial hiding places into their wetland habitats, usually ephemeral ponds (ponds that have been temporarily created by snowmelt and spring rains,) or in wetlands that do not support fish, major predators of salamander eggs and larvae. Breeding activity occurs when water temperatures are 50 to 60 degrees Fahrenheit. The spotted salamander breeds in large groups, while others breed in single pairs. The females often guard their eggs and secrete slime to prevent fungal growth or other destruction. Once hatched, the larvae fall into the pond where they develop until their final metamorphosis. The red-backed salamanders are an exception, being entirely terrestrial, looking for moist habitats to lay their eggs. The unique central newt can produce an aquatic adult, a terrestrial eft (juvenile) and a terrestrial adult.

Salamanders have some other interesting characteristics. Mole salamanders, commonly named the blue-spotted, tiger, and spotted salamanders, exude a defensive, sticky secretion that is foul-tasting to predators. They spend most of their time underground and eat a variety of invertebrates including insects, earthworms, mollusks, and even young rodents. These species can also sometimes be found under rotting logs. The central newt is primarily aquatic, yet also has toxic skin to protect itself. Newts eat earthworms, aquatic insects, snails, and other amphibian larvae. The lungless salamanders have four toes on their hind feet, while other species have five. The red-backed salamander is one of the most abundant species in Wisconsin, commonly found under rotting logs. Mudpuppies are exclusively aquatic, living in lakes and rivers with preferred large, flat rock habitats.

Like other reptiles and amphibians, salamanders shed their skin occasionally, often eating their skin sheds for the nutrients. Some salamanders protect their vital organs by arching their back downward, throwing back their head, and extending their tail over their back. Some salamanders will wag their tails or wiggle their bodies to distract a predator from attacking their heads. For some salamanders, their tails, when grasped, can break off and later partially regenerate. Salamanders also are able to re-grow toes or limbs, or even regenerate their eye tissue.

Salamanders are important for a variety of reasons. The red-backed salamander alone is thought to number in thousands per acre, making their sheer biomass important as a food source to mammals, birds, fish, or reptiles. They are also a predator of many insects or other invertebrates in aquatic or terrestrial environments. They are indicators of local environmental quality, as their permeable skin is vulnerable to pollutants. Maybe most importantly, for many children, one of their first experiences outdoors could be with a frog or salamander. Since my first experience looking for salamanders, I have never looked at a rotting log quite the same. Salamanders are worth carefully searching for as they are beautiful creatures.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Mourning Cloaks

2010-04-05T07:46:00.000-07:00

By Susan Benson,
CNHM Director of Education

The sun is shining, and the last of the melting snow trickles down the driveway. Fluttering down past me goes the first butterfly of the season. A butterfly, in March or April? The main coloration of this butterfly is dark purple-brown, with yellow edges on its wings. Its underside is mottled gray with a lighter yellow edging. It flies straight, flapping alternating with sailing as it moves along by us. This butterfly is a mourning cloak, and it is one of nature and spring’s first happy signs!

Mourning cloaks are named for their dark coloring, which resembles the traditional mourning cloak worn when someone is mourning. In truth, its dark colors warm it faster on the sunny spring days, allowing it to move about when most insects are still not capable of movement. They get warmed up through basking in the sunlight, as they need body temperatures close to that of humans in order to fly. Once they begin their flight their muscles provide enough heat to keep them going. This is passive solar heating at its finest.

Why are mourning cloaks the first spring butterflies? They overwinter as adults, having spent the winter in cryo-preservation. In the fall, mourning cloaks produce antifreeze proteins that they circulate through their blood. These proteins bind to the surface of tiny ice crystals to prevent them from growing bigger and harming the tissues. They also build up higher concentration of sugars, called glycerol, in their blood and tissues to lower the freezing point of their body. Finally, they hide in tree cavities, beneath tree bark, or under leaf litter. It is important, however, that they find a fairly dry place to overwinter so they can avoid contact with ice in the environment that surrounds them. This adult strategy is a different form of hibernation to be sure!

During the spring and summer, the adult mourning cloaks feed on tree sap, especially from oak trees, or fermenting fruit. Occasionally mourning cloaks will be seen at sapsucker holes feeding on sap, or at mud puddles or animal scat where they extract nutrients. When females lay their up to 250 eggs, they prefer willow, birch, aspen, or elm trees. The eggs hatch within about ten days, and the caterpillars are black with red and white spots, with bristly spines on their body. The larvae feed together in silk webs in their large family groups. If they overfeed and wipe out the food supply on the tree, they will move along single file in a line to the next feeding site. By mid-June they leave their host plants, and go off in search of a new site, where they pupate for about 10-15 days. They are believed to be one of the longest-living butterflies, living up to ten months as adults.

With these amazing early spring temperatures, be sure to get outdoors and enjoy the warm weather. Keep your eyes open for a chance encounter with this lovely butterfly. Perhaps you will be lucky and it will fly or land right near you.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Flight & Height

2010-03-29T07:27:00.000-07:00

By Susan Benson,
CNHM Director of Education

While recently talking with some girlfriends, we got on the topic of our experiences speeding along area roads in our cars. Some interesting stories were told. The next morning I was watching a flock of robins migrating through my yard, and started wondering about their speed. How fast do they fly? How high do they fly? Certainly the science of flight speeds in the bird world must be imprecise given that birds deal with head or tail winds, or barometric pressure. Does bird age affect their flight? How can we tell if a bird is flying at its top speed, or is just cruising along? What estimates exist on flight speed and altitudes was a question I wanted to answer.

A robin has been measured at 30 mph, while an arctic loon can fly at 56 mph, the common loon at 90, and the killdeer and wood duck at 55 mph. A canvasback duck can reach 72 mph, and a tiny hummingbird has been “clocked” at 27 mph, but at 50 mph with a tail wind. This top speed, by the way, rivals a Canada goose – apparently size is not an indicator of speed!

Bird air speed has been estimated from cars and planes. Doppler radar, the device similar to that which police use to catch speeders, has been used to measure ground speed of birds. Alternatively, using wind speed measurements with an anemometer, scientists have estimated bird airspeeds. These measurements were also calculated with power requirements. For example, there is a top speed with which a bird can fly, and the speed with which it usually does fly. Birds appear to minimize their energy use, or metabolic rate, and maximize the distance they can travel during the time in which they expend their energy. A bald eagle that is searching for prey may minimize their energy expenditure by soaring while using a thermal, or bubble of warm air. A bird might also choose its maximum speed when in flight from a predator. These studies found that a gull can fly 15 to 28 miles per hour (mph) without raising its metabolic rate more than 15 percent. Some bird species that have a courtship flight reach their maximum speeds during these flights. Small woodland birds fly faster in open areas, while birds in flocks fly faster than when flying alone. During a chase, a duck can reach up to sixty mph, while a peregrine falcon can reach 200 mph. That is fast!

How high do birds fly? Birds have been spotted on the top of Mount Everest, at more than 29,000 feet, and in the Himalayas at 25,000 feet. Even the smallest warbler has been seen flying at an altitude of 9,000 feet, a real feat since breathing at high altitudes, mixed with cold air can make flight challenging. On the flip side, the emperor penguin has been recorded swimming at an ocean depth of 875 feet.

Most birds fly below 500 feet except during migration. Long-distance migrants have been observed flying at 5,000-20,000 feet. Whooper swans were observed by a pilot at 29,000 feet. This is amazing considering the air at 20,000 feet has less than half the oxygen at lower levels. Vultures will rise to over 10,000 feet, presumably to scan larger areas for food, and to observe where other vultures are feeding. Radar observations have shown that nocturnal migrants fly higher as well. Scientists believe that this might make for better tail winds, and cooler air decreases water loss due to evaporation and allows migrants to regulate their body temperature with greater ease. Landmarks might be easier to locate from up high. The birds also do not have to do battle with fog, clouds, or other physical barriers. On the other hand, some water birds and land birds have been observed migrating low over the water, rarely rising above 200 feet. What amazing diversity birds can show!

We often hear stories of birds flying “a mile a minute,” and although we know that most birds do not reach that accelerated speed for long, we can certainly appreciate their abilities. As I sometimes fly around “a mile a minute” in my own personal life, nature and birds can be a reminder to slow life down for a moment, or two, or two thousand, giving us time to enjoy the beauty around us.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Tasty Treats

2010-03-22T11:23:00.000-07:00

By Susan Benson,
CNHM Director of Education

Just as birds have evolved to fill most habitats on Earth, and have also evolved an amazing diversity of bills, so too is it interesting to study what birds eat. To say that a bird “eats like a bird” is misleading, as birds have very high metabolisms, and so need more food than many other animals. For a human to maintain a metabolism as high as a hummingbird, it would have to eat one and a half times its own weight daily. Imagine how many quarter pounders that would take! Take a few moments to learn about the fascinating diversity of bird foods and feeding habits.
• Grebes continuously eat their own feathers, and can feed feathers to their chicks. This is thought to be a way to protect their stomachs from the sharp bones of the fish prey that makes up the bulk of their diet.
• Peregrine falcons have a strange notch along the lower edge of their upper mandible (beak.) When they catch their prey, if their fast attack does not kill their prey, they can quickly slice the spinal cord of their prey with this notched beak, killing the prey instantly.
• The anhinga uses its bill as a spear, diving through the water to stalk for bluegills and other small fish. Once their meal is speared, they toss their beak into the air, throwing the fish into the air where they can grab and swallow it – head first. Great blue herons, however, do not spear their fish prey, and would have a more difficult time removing the prey from their beak if this did occur.
• Green-backed herons have been observed taking bread crumbs from a picnic area, dropping them into shallow water, and then diving in to feed on the minnows that are coming to feed on the crumbs.
• To determine if owls use their sight or hearing, scientists experimented with barn owls. In a completely darkened room, the owls still killed the mice. To isolate whether they used hearing or infrared vision (to detect body heat,) scientists released mice with balls of paper tied to a length of string. Through this experiment, designed so the paper would make more noise than the mice, they discovered that the owls attacked the paper, proving that owls hunt by sound.
• Most birds are known to eat fine gravel, which has no nutritional value, but assists in the birds gizzard, grinding seeds on which a bird feeds. Turkeys can have up to two ounces of grit in their gizzards, and moas, an extinct bird, swallowed up to five pounds. Penguins, however, do not eat seeds, and apparently use rocks as a ballast for swimming.
• Turkey vultures, a bird that eats the less desirable food, carrion, have interesting adaptations to assist them with feeding. First, they have a surprising sense of smell and sight to find their dead food. When they have been successful, they have no feathers on their head to keep their body cleaner and more “sanitary.” They will wipe their head on the ground, or preen themselves to stay clean.
• Some birds are generalists, and eat a wide variety of foods. Others are specialists, and depend on more specific food sources. An ivory-billed woodpecker feeds exclusively on wood-boring beetle larvae. The acorn woodpecker on mostly acorns or other nuts that gets stored in communal caches. The storm-petrel eats floating oil from dead marine mammals. Ospreys eat fish, while black–necked stilts eat brine flies. The Wilson’s phalarope spins rapidly in the water and feeds on insects as they are swirled to the surface. An American woodcock eats earthworms. A northern flicker eats ants. A groove-billed ani eats parasitic insects on cattle. Finally, the red and white-winged crossbills eat conifer seeds they pry free with their crossed beaks.

Such a smorgasbord of tasty treats does the bird world eat. I will never look at a buffet in the same way, and appreciate my “generalist” lifestyle of eating. Now that spring seems to have sprung, enjoy watching birds outdoors, as you never know what you might see them eating!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Hairy & Downy Woodpeckers

2010-03-15T11:33:00.000-07:00

By Susan Benson,
Director of Education

“What are the red and white woodpeckers at my feeder? Are they the same bird or just an adult and young bird?” These are questions I have been asked by several people recently. I have also enjoyed both of these species at my own suet feeders. They are two species, the downy and hairy woodpecker. These birds have many similarities. They are common throughout most of North America. They both visit our suet feeders. They are the only common woodpeckers that display a vertical white stripe on their back. The males of both species have a red patch on the back of their head. However, there are also many differences between them, some obvious, and some more subtle.

Two features that make the downy woodpecker easier to identify are the size and bill. The downy woodpecker is much smaller, approximately six to seven inches long. Their bill is shorter, smaller than the width of the head, and about one-third as long as the hairy woodpecker. The white outer tail feathers are barred in black, giving the bird a spotted effect. They also have a squeaky call and slower drum in comparison to hairy woodpeckers. There are other characteristics and behaviors to look for when comparing downy and hairy woodpeckers. The hairy woodpecker forages along trunks and main branches of large trees, with an erect posture, while downy woodpeckers use smaller branches.

What makes these two woodpeckers different? The downy woodpecker joins flocks of chickadees and nuthatches. Flocking with mixed bird species is an advantage as these birds spend less time watching for predators, and have better luck finding food. During the winter, males and females split up to look for food, and males seem to prefer small branches and weed stems, while females feed on larger branches and trunks. Both sexes of “downys” find foods that larger woodpeckers cannot, so downys can be found feeding on insects they find on plant stems and goldenrod galls, round ball on the stems, in which fly larvae are living inside. Downy woodpeckers also eat beetle larvae, ants, or caterpillars in wood or tree bark. They also eat berries, acorns and grains, and are common suet and sunflower seed eaters. They have been observed drinking from hummingbird feeders. They sometimes even hop across the ground for food.

Downy woodpeckers excavate nesting holes, taking up to three weeks to make, with an entrance that is round, but only up to 1.5 inches across. The best place to look for an entrance is in a small, dead tree stub that is around seven inches in diameter, on the underside of the snag. Sometimes their excavations can be found inside of the walls of buildings. They prefer open deciduous woodlands, and their dead nest trees are sometimes filled with fungus that makes excavation easier. They drum against wood as a way to find their mate or to set up territory, and downys will drum more in the early morning.

Hairy Woodpeckers are more common in mature woodlands, and will be found in coniferous deciduous, or even mixed forests with medium to large trees. More than seventy-five percent of their diet is made up of insects, as they prefer wood-boring beetle larvae, bark beetles, ants, and moth pupae. They eat many other types of insects as well. They will drink sap that is leaking from trees. They are often seen cleaning up a site after a pileated woodpecker has finished. Around twenty percent of their diet is made up of fruit and seeds, and they also visit suet and sunflower feeders. They do not feed on weed stalks or plants like the downies, but sometimes forage at the base of trees.

The entrance to a hairy woodpecker nest is a cavity with an opening two inches tall and 1.5 inches wide that takes up to two weeks to create. “Hairys” are a little different as they excavate their nests in the dead stub of a living tree, or in a dead tree, also with their entrance on the underside. The cavity is often in a branch or stub that isn’t perfectly vertical, with the entrance hole on the underside, which perhaps keeps flying squirrels or other woodpeckers from taking over their nest. These birds also drum against trees, more quickly than downy woodpeckers, and their drum is about ten times per minute.

I find that writing these Nature Watch articles makes me look at the beauty in nature I often see in a different way. So, for those who are looking to identify these woodpeckers, or other birds at their feeder, here is a simple tip. First take a look at the overall size of the bird. Size is a reliable field mark, but is difficult to judge when looking outdoors. Some people will measure their feeder, or mark different lengths on their feeders to help them judge the size of birds visiting their feeders. Happy birding!

Gray & Fox Squirrels

2010-03-08T11:31:00.000-08:00

By Susan Benson,
CNHM Director of Education

I must be crazy. While others are trying to squirrel-proof their feeders, this past Sunday I decided to feed them. I wanted to do some “scientific” observation of squirrels eating, so I put out some piles of sunflower seeds near the sliding glass doors on the patio. One that I’ve dubbed “chicken pants” would not come near, but along came another “braveheart” that wasn’t at all afraid. I watched it eat for a while, sharp claws and teeth at work, and then along came “chicken pants” who although was afraid of me, was not afraid of “braveheart.” I had never heard squirrels growl, but that was the only way I could describe their territorial attempts to claim the food piles. These two squirrels did not quite look alike, so I decided to research a little deeper.

In this part of Wisconsin we have two types of tree squirrels, the gray and the fox squirrel. The fox squirrel is bigger, and its fur is brown to gray, with a bushy tail that ends with tawny-tipped hairs. The gray squirrel is just a bit smaller, with gray color and a bushy tail tipped with white. As I read about these two squirrel species, I realized that “braveheart” was a fox squirrel, and “chicken pants” was a gray squirrel. We do indeed learn something every day.

Gray and fox squirrels have very sharp claws for climbing trees, and vibrissae, thick hairs or whiskers that are used as touch receptors to sense in their environment and help find their way in dark tree cavities. The conspicuous bushy tail of both squirrels assists them with communication, balance, covering as a blanket, and umbrella. Both squirrel species are both scatter-hoarders, hiding food in many small caches for later retrieval. Some cache sites are for shorter-term use that they eat within hours or days, or sometimes will re-bury at another site. It is believed that both squirrels make thousands of caches each season. Fox and gray squirrels both have very accurate spatial memory, using distant and nearby landmarks to retrieve their caches. Their sense of smell is then used as they approach more closely to the cache. In spite of these advantages, they often leave behind food supplies that germinate and become new trees.

Fox squirrels depend primarily on tree seeds for food, especially acorns and hazelnuts, and will also consume buds, fruits, cultivated grain, and insects. Gray squirrels have a more diverse diet, eating acorns and other tree nuts, fruits, fungi, insects, inner tree bark, sap, and underground sections of plants. They will also eat small rodents, including other squirrels, and will raid bird nests for eggs and young.

Gray squirrels are one of the few mammal species that can descend a tree face-first, turning their feet so the claws of their hind paws are pointing backward, gripping the bark. Fox Squirrels are non-territorial, and spend more time on the ground than the gray squirrel. They are still, however, agile climbers. They can span fifteen feet in horizontal leaps, and fall twenty feet to a soft landing on a limb below.
Both species of squirrels construct nests called “dreys,” made of dry leaf and twig platforms high in the trees. Gray squirrels will use old woodpecker holes as dens to raise young, but only build dreys when cavities are not available. Fox squirrels also have winter dens that are usually hollow cavities in trees, in which communal denning can occur, and the home itself can be used by a succession of squirrels for thirty or more years.

Gray and fox squirrels have a large vocabulary. Gray squirrels use sounds and posturing, including a squeak similar to a mouse, a low pitched sound, a raspy, repeated “mehr” sound, and a chatter. Fox squirrels cluck, chuck, and warn the world of nearby threats with screams. They make high-pitched sounds when mating. When threatening another fox squirrel, they stand upright with their tail up high, flicking it.

Gray squirrels prefer mixed hardwood forests with mature, nut producing trees. Grays will usually stay very close to home, with a territory as small as 1,000 feet. Fox squirrels prefer agricultural areas mixed with forested woodlots, with a home range of 10-40 acres.

As I am writing this story, my fiancé has complained to me that these squirrels just chewed up a gas can. Are they chewing at something like this simply to keep their teeth sharpened? Is there anything they won’t chew? For whatever reason this squirrel chewed, we all know the rodents in our world bring us the occasional frustration, and for the most part, entertainment and joy.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Bills

2010-03-01T08:16:00.000-08:00

By Susan Benson,
CNHM Director of Education

Just think about a crossbill, spoonbill, bluebill, ivory-billed woodpecker, great hornbill, channel-billed toucan, yellow-billed stork, saddle-billed stork, or shoebill stork – all birds that are named because of their bills. Others are named for their mandibles, which is what the top and bottom parts of a bird’s bill are called, such as the black or chestnut-mandibled toucan. Then ponder the use of your own mouth, and compare it to that of birds, which use their bill for eating, killing prey, probing for food, grooming, manipulating objects, courtship, and feeding their young. Bird bills show amazing diversity, both in physical anatomy and their use. Check out the following bill facts:

• Bill anatomy – the jaws of a bird’s bills are made of a hollow or porous bone designed light for flight. The outside of the bill is covered with keratin, the same material in our fingernails. Bird bills have two holes called nares that connect to their respiratory system. When birds open their mouths, the lower jaw does most of the movement. Their bills continue to grow throughout their lives in order to replace the wearing that occurs at the tips.
• What are some of the common bill types? First, there is the probe, such as hummingbirds, that have long straw-like bills to sip nectar from flowers. Next are the chisel-like beaks, such as woodpeckers, that chisel for food or cavities. Some birds, such as herons or mergansers have spears, bills with serrated edges and a hooked point for grabbing fish. Birds of prey have hooked bills for tearing apart their live prey into pieces small enough to swallow. Blackbirds, meadowlarks, and warblers have tweezer-like bills for probing for insects. Flycatchers and goatsuckers have wide bills surrounded by a net of bristles that funnel flying insects into their mouth while in flight. Nutcrackers such as grosbeaks, sparrows, and finches have thick, conical beaks, for cracking open the hard outer shells of seeds. A kitchen strainer is similar to the edges of a duck's bill which is fringed to strain plants, seeds, and small invertebrates from mud and water. Finally are the burrowing birds, such as stilts, woodcocks, or avocets, which have thin, probing bills to jab in the mud.
• It is worth peeking at the local American woodcock bill, which has a flexible tip specially adapted for probing into moist soil in search of earthworms. It is believed that this bird steps heavily, causing worms to move more in the soil. Their beak then probes and feels the worms in the moist soil.
• Crossbills also have an odd, crossed bill that assists them with getting into tightly closed cones. Their jaw muscles are strong, so the bird places its bill tip slightly open under a cone seed, and then bites down. The crossed tips then push the cone scale up, exposing the seed underneath.
• Looking around the world, there are interesting bird bills as well. The sword-billed hummingbird has a bill is longer than its body. A skimmer’s lower mandible is larger than the top mandible, allowing them to place this part of their bill into the water, flip fish into the air, and catch them. The shoebill has a bill that looks like a shoe, and these birds use their bill in muddy waters, preying on fish, frogs, young crocodiles, invertebrates and small mammals.
The United State Fish and Wildlife Service reports that birdwatching brings in $36 billion annually to our economy, and its no secret why. Having a bird life list is not enough for many of us. Imagine being able to watch a skimmer skim for fish, or to observe with binoculars a crossbill pull seeds out of a cone. These kinds of experiences are priceless.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Tongues

2010-02-22T09:34:00.000-08:00

By Susan Benson,
CNHM Director of Education

I love my tongue. I love it as I sing with it, taste with it, talk with it, whistle with it, or hoot with it. Just the thought of dark chocolate melting on my tongue makes me smile. Oh the joy my tongue can give me! Our human tongues are important for these reasons, but for most birds, their tongue is used for a reason that doesn’t have much to do with communication. Their tongues are used more for grasping or manipulating food. Check out these bird tongues and their functions:

• Most sadly, birds do not have tongues for tasting. Birds have the misfortune of having almost no taste buds. Chickens only have twenty-four taste buds, and parrots’ taste buds number in the hundreds.
• Most birds have a simple tongue with a flat, triangular blade with “papillae” at the back of the mouth that point backward, ensuring that their food goes in one direction. Penguins have a tongue covered with backward pointing spikes to help swallow fish.
• In cormorants, pelicans, or kingfishers, which scoop and swallow their food whole, the tongue is very small.
• Brush-tongued lories have a tongue with a small brush at the tip that they use to collect flower nectar. Hummingbirds have long, hollow tubes forked at the end into two curled channels that allow them to dip into a flower, three to twelve times a second, to lap up flower nectar. It is believed that capillary action causes the liquid to be pulled up into the troughs. When the bird retracts its tongue, pressure on the tongue squeezes the liquid out.
• For many birds, their tongues are supported by five tongue bones, bones and cartilage called the “hyoid apparatus.” Their tongue is harder and less flexible than human tongues.
• A woodpecker has a barbed tongue, with a spear-like tongue bone that can extend up to four times the length of its beak to grasp insects from a tree. Their tongue, as part of the hyoid apparatus, wraps around the skull and anchors at the base of the bill. Some have a sharp pointed top to spear wood-boring insect larvae. Others have a tongue tip that has backward pointed barbs to help extract insects from the holes, and the tongue is coated with sticky saliva to help stick to the prey. Sapsucker tongues have hair-like extensions on their tongue tips to capture sap through capillary action. In some woodpecker species, part of the hyoid process has joints between the bones of the skull and upper jaw with muscles to absorb the shock of hammering.
• Birds that feed on seeds or fruits, such as parrots, are likely to have well-padded, thicker tongues that also enable them to make sounds that we enjoy so much we often desire them as pets.
• A ducks upper bill is specialized for filtering out food from the water. They get a mouthful of water and the tongue moves the water out. A flamingo has spiny barbs on the sides of its tongue to filter out microorganisms.

“Sally sells seashells by the seashore” is a tongue twister that we all may know well, but knowledge of birds’ tongues brings an entire meaning to the concept. Be sure to watch birds around your home or feeders in a new way – you just might see their tongues at work!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Bird Eyesite

2010-02-15T07:41:00.000-08:00

By Susan Benson,
CNHM Director of Education

Did you know that if an owl could read, it could read a newspaper from the other end of a football field? Or that a golden eagle can see a rabbit from two miles away? Or that our eyes would need to be the size of grapefruit in order to have the same visual ability of birds of prey? Birds truly have amazing visual abilities!

Birds’ eyes sometimes weigh more than their brains. They can see with similar clarity to that of humans, but they can process the information they see much better than humans. All birds can see with binocular and monocular vision. This means that their eyes can work together to see straight ahead, and can also see out of each eye independently.

Monocular vision is the reason that birds have their eyes located in different places on their head. The pigeon has eyes on the side of its head, which enables them to see in all directions except right behind themselves. An American robin cocks its head to one side, appearing to be listening. In reality, it is turning its head to use its monocular vision to spot an earthworm on the ground. The American woodcock's eyes are closer to the top of their head to enable them to see behind.
For bald eagles, this combination of binocular and monocular vision means they can see fish in the water from several hundred feet above, quite an accomplishment since fish are counter-shaded with darker colors on top to make seeing from above harder. Additionally, eagles and other birds of prey have more visual cells – hawks have one million cells compared to humans which have about two-hundred thousand cells. Eagles also have color vision. Combine these skills, and an eagle can fly 1000 feet above an open area and spot prey for an almost three square miles.

The ability to see color is a big advantage to birds. Birds have an area in their retina which contains colored droplets of oil. Kingfishers have more oil than other birds, and scientists believe this helps block the glare from the water. Pigeons have brighter drops of yellow oil, which might help dull the brightness in the sky.
Birds, like humans, also have rods and cones. Rods let in available light, and cones detect color. Nocturnal birds like owls have more rods, which help them detect prey in low light levels. They also have fewer cones, which help discriminate shapes and colors, making it difficult for owls or other nocturnal birds to see finer details. Birds more active during the day have more cones, since the presence of light is needed to see color. In addition to this, birds can also see ultraviolet light—part of the light spectrum that humans can’t see. Many birds show different ultraviolet patterns that are not visible to humans, but are believed to assist birds with courtship. Birds whose male and females look the same to us look different from an ultraviolet perspective. This ultraviolet receptor might also help birds with foraging for food, as some waxy berries and fruits reflect ultraviolet light to perhaps advertise their location.

A “bird's eye view” or “an eagle eye” are words that take on new meaning when we realize how complicated bird vision really is. It also makes it more understandable why “sneaking” up on birds to view them closer can be so difficult. That elusive warbler will always continue to be hard to find when our slightest movement is so easily detectable. However, please do not let that dissuade anyone from doing what we can to keep on observing these beautiful creatures!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Pileated Woodpeckers

2010-02-09T12:16:00.000-08:00

By Susan Benson,
CNHM Director of Education

Thunk! Thunk! Thunk! This was the sound I heard outside my house while building a snowman in the recent wet, heavy snowfall. I looked over and with great excitement, spotted a pileated woodpecker. I watched while it pounded against the base of a tree, snow flying as the bird scooped it behind itself. These large woodpeckers are almost crow-sized, with a wing spread of up to 30 inches. This bird, a model for the cartoon character Woody Woodpecker, is mostly black with a large red crest on its head. White stripes run down the face to the neck. Their wild laughter-like call and drumming can be heard long distances through a forest. There are a lot more interesting facts about pileated woodpeckers!

What is their habitat? Pileated woodpeckers prefer mature forests, but have adapted to second-growth forests. In younger, select-cut forests they use large trees left behind.

What do they eat? When pileated woodpeckers hear an insect under the bark, they begin pecking with their beaks. They have a thick skull to avoid headaches. Their tongue is long with a sharp end for spiking insects inside the tree, and also has a sticky section to attach to the insects. This woodpecker prefers carpenter ants and wood-boring beetle larvae. Their straight bill is also good for collecting fruits and nuts. They seem to be great carpenters, boring large holes into tree trunks. They can pry off long slivers of wood to expose their food, and make elongated holes so they can “dig” deeper into the tree and still accommodate their body size. These excavations are so extensive that they can attract other woodpeckers and even wrens to the same feeding sites.

How else do they use their carpentry skills? Pileated woodpeckers raise their young in tree holes, using a new hole each year in a dead tree or branch. It can take up to six weeks to pound out their new nesting site. A roosting site often has multiple entrances. Sometimes their cavities can cause a smaller tree to break in half! Once the holes are abandoned, they provide homes for other forest songbirds.
What are other interesting pileated woodpecker facts? If an egg falls off the nest, they have been observed moving their eggs, a rare habit in the bird world. A sad fact is that because they often choose taller, mature trees, they face danger from lightning strikes.

Pileated woodpeckers are unforgettable. Once you see one, you will never forget what it looks like, and once you learn to recognize their laughing call, you can laugh in response just hearing it. It is also worth trying to catch a glimpse of it in flight with its black body and white wing linings, mixed with its swooping flight. And how is it pronounced – with the long or short i? According to the resources I searched, either way works!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Saw-Whet Owl

2010-02-02T11:59:00.000-08:00

By Susan Benson,
CNHM Director of Education

He came out on his porch, and right on the railing was an owl – a saw-whet owl. The owl was startled, and flew to a nearby tree, where a he watched it for a while at his house. I listened to this story at the Museum, wishing I could have seen this myself as the saw-whet is a bird that continues to be on my must-see life list. I have not yet had the fortune to observe one, but think they are spectacular birds.
How do we identify a saw-whet owl? These owls are only seven to eight inches tall, have a white face outlined in brown and white, with yellow eyes but no ear tufts. Their underparts are white and streaked with brown. They have an asymmetrical skull that makes their head sometimes appear distorted.

Behavior or location can also help with identification of this bird. We can best find the northern saw-whet owl in deciduous and coniferous forests that have thicker understory or shrubs. Other preferred habitat includes areas with older deciduous trees that have existing woodpecker cavities, and forests near wetland habitat. During the day saw-whets roost in tree cover close to the ground. Saw-whet owls tend to shuffle their feet when sitting, and look larger when in flight because of their broad wings. When threatened, they stretch their body out to look like a branch, sometimes bringing a wing around to the front of their bodies. They also tend to stay in one place rather than flying away when scared, causing people to think they are tame. We can recognize their call, which occurs mostly between March and May and sounds like a repeated, whistle-like “hoop” that can last for hours without a break. Their name comes from their alarm call that sounds like the whetting of a saw.

Saw-whet owls hunt at dusk and dawn, waiting until they spy prey, then swooping down to catch them from low hunting perches and heavy shrub cover. They feed mostly on small mammals that include deer mice, shrews, voles, squirrels, bats, flying squirrels, and house mice. Frogs, insects, and birds up to cardinal size can be killed by saw-whets. Sometimes these small owls will eat a mouse in two meals. When prey is plentiful, they will often eat only the head of their prey. In winter they will also kill several mice quite quickly and cache them in hiding places, saving them for a later date when they can thaw out and eat the carcass. What a clever use of nature’s freezer!

Night-time is truly a great time to enjoy the outdoors, even in winter. So many nocturnal animals can bring us the same exciting discoveries that diurnal animals can. Sometimes we do not have to go far, as the next observation might be right outside our doorway!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Red-Breasted Nutchatches

2010-01-27T11:43:00.000-08:00

Susan Benson,
CNHM Director of Education

Could there be anything more perfect than a nuthatch? I sat this morning for a few moments of solitude, in front of the new bird feeder, watching the red-breasted nuthatches visit the sunflower seed feeder. Having it three feet away from my window made for such up-close inspection as I sat, without moving. I watched as it tossed away the seeds to the ground, amazing me with its beauty. I live in the perfect habitat for red-breasted nuthatches, a mixed deciduous-coniferous forest, with mature stands of decaying large trees. I knew these monogamous birds stay paired up throughout the winter. Then, as I watched it eat from further away, I thought of its appropriate name. The common name, nuthatch, comes from the Eurasian Nuthatch's habit of wedging an acorn into a bark crevice and then breaking it open with blows from its bill. The nuthatch family name is Sittidae, and sitte is a Greek word for "birds that peck on the bark of trees." These are just some of the interesting facts about this well-loved bird.

When building their nests, both male and female red-breasted nuthatches excavate a hole that can take up to 18 days to build. They are known to steal the soft lining from other birds’ nests for their own. Then they repeatedly smear pine pitch and insects around the entrance of their nest to sanitize it. To apply the pitch, they use their beak or a piece of bark with the pitch on it as an application tool. The males will place the resin on the outside, and females place it on the inside. It is believed that the pitch and defensive chemicals of the insects keeps out parasites. It might also discourage predators. The birds prevent it from sticking to themselves by diving right through the hole. It is dead or dying aspens that these birds prefer for their excavations because of the soft wood.

In summer, red-breasted nuthatches eat beetles, caterpillars, spiders, ants, and earwigs, and they raise their young on 100% protein. In fall and winter they tend to eat conifer seeds. They will transport cone seeds from a heavily laden conifer and hoard excess food in nearby larders to help them get through winter. They shove the food into bark crevices and cover them with pieces of bark, lichen or pebbles. Red-breasted nuthatches also eat from bird feeders, often choosing the heaviest food item available, jamming it into bark and hammering it open.

Red-breasted nuthatches have interesting behaviors. One of most comical behaviors to watch is the typical nuthatch movement. Red-breasted nuthatches move quickly on trees, zigzagging downward, relying on their backward-pointing toe to grip the trunk. This advantage helps them see insects hiding in crevices that woodpeckers and birds that only move upward on a tree cannot see. Another behavior seen mostly in winter is when red-breasted nuthatches join foraging flocks of chickadees and other small birds. Also, small groups of nuthatches will spend the night together in tree cavities. Finally, when listening, their call is a “yank, yank” that sounds a bit like a high-pitched tin trumpet.

Did you know that due to the weaker feet of a red-breasted nuthatch, they bathe by puffing their wings out during a rain storm? This is just one more fact I couldn’t leave out, so I end with that nature nugget. I can think of no reason that we shouldn’t all be nuts for nuthatches!

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and new exhibit, Our Shared Planet, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

Subnivean Temperatures

2010-01-21T11:25:00.000-08:00

Nature Watch

By Susan Benson,
CNHM Director of Education

The subnivean space – perhaps it sounds like something out of a science fiction novel, something you might find on a journey to the center of the earth. However, it is not as mystifying as one might think. Quite simply, the subnivean space is the layer between the ground and snowpack. While the snow cover builds up, the ground gives off heat, creating water vapor that condenses and freezes under the bottom layer of snow, creating small spaces at ground level. Many small animals would never survive the winter cold without this space.

The minute a snowflake falls, it begins changing its shape. It can be affected by the internal snowpack characteristics and the external weather conditions. The first deterioration of a snowflake begins as a “destructive” change, in which the snow grains become more rounded. The unequal temperature distribution in the snowpack causes the water molecules to melt, changing the radiating arms of the snowflakes into a rough, spherical ice particle. These ice grains can then connect together, until they are roughly the same size. This metamorphosis occurs more quickly when air temperature is warmer, and is also influenced by wind or the weight of the snow above. It is this destructive metamorphosis that makes building snow shelters so effective.

The snowpack also is exposed to constructive metamorphosis, a process in which the temperature changes from the bottom to top of the snowpack is significantly different. The snow’s upper part is affected by the air temperature, and the lower part is warmed by the ground. Heat is conducted very slowly upward through the snow, affecting the water vapor distribution, and creating a 100% relative humidity in many of the air spaces in the snow. This process causes the ice crystals at the bottom of the snowpack to get continually smaller. Eventually, they form “depth hoar,” brittle, loosely arranged crystals that create easy movement for small mammals as they search for food under the winter snow.

The third factor which affects snow is the “melt metamorphosis”, in which happens when the snowpack is impacted by above freezing temperatures. Surface snow melt percolates down through the snowpack, encounters lower temperatures, and refreezes. As it freezes, it releases heat, bringing the entire snowpack to a more equal temperature. Rain and fog can also cause a similar effect.

Doesn’t the sun’s solar radiation warm the snowpack as well? We all know that spending a day in the snow in bright sunlight is shocking to our eyes, because snow is highly reflective of incoming solar radiation. Perhaps better than a mirror, snow reflects 75-95% of the sunlight hitting its surface. This means that a small amount of solar energy is available to raise the temperature of the snow. However, aging snow, as it accumulates dust, can decrease the sun’s reflection to as low as 45 percent.

It is easy to see that although complex processes occur, the snowpack provides amazing insulation for the winter survival of organisms. How much snow is enough? One theory is that 20 centimeters is a critical depth. The subnivean layer and its temperature and effectiveness for animal survival can also be affected by the type of snowpack metamorphosis that has occurred. By the time the snowpack reaches 40-50 centimeters, the subnivean environment temperature is almost constant.

Most importantly to our animal world, it is as if the snow peels away from the ground, leaving pockets where mice, voles, and shrews spend the winter. Some predators such as weasels live there too. Under that white snow in your yard there is an entire food chain still at work! Next time you are out for a ski, hike, or on a snowmobile trail, look at the edges of the trails to see if you can observe tunnels created by animals living in the snow.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Bobcats

2010-01-13T10:34:00.000-08:00

By Susan Benson,
CNHM Director of Education

Coming home one night, I spotted yellow eyes in the road ahead. It didn't look like the same color made by white-tailed deer, so I took even closer notice. As I approached, I was excited to see a bobcat. I knew almost immediately what it was as I made those split-second decisions - the animal was about twice the size as a domestic cat, and although I couldn't see its prominent ear tufts, I caught sight of the short 'bobbed' tail that gives these cats their name. How thrilling it was to have visual evidence of these creatures around my home!

The physical attributes of bobcats vary depending on their location. Bobcats in forested northern territories are usually bigger with darker, dense fur while further south they are smaller small and have lighter coloration. Their coat takes on a reddish coloration during the warmer months, and the markings camouflage this amazing carnivore as they hunt through thick underbrush.

Despite their smaller size, bobcats are very successful predators due to their diverse food choices and adaptability. They can take down prey that are eight times their own weight, choosing first from snowshoe hare and cottontail rabbit populations. They also eat squirrels, birds, porcupines, mice, voles, shrews, birds, insects, and reptiles. Less common food sources such as deer, foxes, or skunks are used when other food is scarce. Bobcats rely on stealth, sneaking up to the prey, then using their long hind legs to produce great bursts of speed, reaching nearly thirty miles per hour. When hunting a rabbit, for example, they will often wait until a rabbit approaches within 15-35 feet, and then pounce. Such sneaky hunting tactics!

Bobcats are solitary, and mostly nocturnal, being most active at dawn and dusk. For those who search for their own bobcat discovery, bobcats prefer heavy forested areas, alder thickets or coniferous swamps. It is estimated that an average density of bobcats varies, but is about 1 bobcat every 25 square miles. Males move a distance of up to 2.6 miles per week, while females move about one mile less. They often use roads or game trails to move between food or resting places, especially in deep snow. If you have a bobcat story to share, please email the Museum at info@cablemuseum.org, or post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

________________________________________

Cable Natural History Museum
PO Box 416

Red Squirrels

2010-01-07T12:09:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Last week’s observation of two squirrels chasing each other around the tree brought back funny memories of my interactions with this animal. For years I had appreciated these small red critters as they scolded me with their “chuck, chuck” sounds while waving their tail and stomping their feet at me. This appreciation changed a bit when one day, while napping on my couch, I heard a noise in the kitchen. I looked with surprise, and there, on top of my refrigerator, was a red squirrel. That scolding sound took on a new meaning to me as I spent the next half hour trying to encourage this squirrel to leave the house. After a lengthy search, I still could not figure out how this squirrel found entrance to my home. The next day when I returned home from the Museum, I noticed the artwork on the walls all cockeyed – that squirrel had enjoyed another day while I was hard at work, “playing” inside my house. A few days later, I discovered the toilet paper had been unrolled and pulled all over the house by this mischievous squirrel. Its playful antics ended when I discovered its entrance through the dryer vent (clever, aren’t they?) Now I consider myself fortunate to enjoy them outside of the house.

Active mostly at dawn and late afternoon, red squirrels may spend up to eighty percent of their time foraging for food. One of their main food sources is pine seeds. In the fall, “reds” will cut green cones from trees and store them in their piles, or middens, under logs, at the base of trees, or underground. Up to a bushel of food can be stored in one of these piles. They are able to relocate their buried seeds a few inches underground and deep below the snow with their great sense of smell. However, many midden piles are not found, giving red squirrels an important role as a re-forester. Additionally, “reds” may eat up to two-thirds of a pine seed crop in an area each year. They also eat acorns, beechnuts, seeds, berries, birds’ eggs, and fungi. Red squirrels will bite into a sugar maple’s xylem, letting the sap ooze out, to return later when the water has evaporated and the sugar content is higher.

It is around this time of year when breeding for red squirrels begins, which explains the two red squirrels I observed running around the tree for a dizzying amount of time. “Red” makes its nests in a variety of places including hollows in the ground, in tree hollows, logs or crotches in trees.

Boomer, chatterbox, chickaree, and pine squirrel are just some of the names for a red squirrel. Their scientific name is Tamiasciurus hudsonicus. Tamiasciurus is Latin for “the steward who sits in the shadow of his tail,” and hudsonicus relates to Hudson Bay, where this species was first named. It is only the northern two-thirds of Wisconsin that enjoys the “chatter” of this squirrel that prefers coniferous and mixed forests. If you have your own red squirrel story to share, please email the Museum at info@cablemuseum.org, or post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Red Fox

2009-12-31T11:40:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Have I mentioned lately how much fun it is to live in the northwoods? I continue to be amazed by what we can see in the natural world in one or two days. On my own property, in the last week, I’ve seen wolf tracks; a bobcat, whose tracks I searched for the next day; two red squirrels chasing each other around a tree, for what seemed like a dizzying amount of time; white-tail deer tracks, everywhere; and what appears to be a red fox bed site. In a few days’ time I had the content for several weeks Nature Watch articles.

I was exploring the forest behind my house. I found the beds on a small hill, four disc-shaped beds with fox tracks leading up to them. I smiled with such pride at having found them in the forest, probably one hundred yards away from my house. I had to find out more. Was it mostly likely a red fox or gray fox? Was it one fox returning for several nights, or two? I had to know the answers.

Was it mostly likely a red fox or gray fox? Gray fox are not as common in the northern third of the state, as Wisconsin is the northern part of its range. Therefore, I assume that the bed sites were made by a red fox.

Was it one fox or two? In December, males and females have paired up in preparation of the breeding season, which means the bedding sites I viewed are possibly from two animals. Foxes sleep while curling their long bushy tails around their body and over their nose and foot pads to keep warm. Red foxes are nocturnal, with most of their hunting taking place two hours before sunset until a few hours after sunrise. Able to run up to thirty miles per hour, they can travel up to nine miles in one night in search of food.

In the winter, red fox eat mostly meadow voles, mice, snowshoe hare, and cottontail rabbits. During other seasons they will eat squirrels, songbirds, eggs, insects, snails, crayfish, berries, fruit, acorns, corn, or grass. The red fox is a solitary hunter that searches field edges or forest while search for their prey. They have excellent eyesight, as the slight movement of an ear may be all that is needed to locate a rabbit or squirrel. They can smell eggs or young rabbits in their nests. Their large ears allow them to locate a sound within one degree of its actual location. Additionally, fox can hear mouse squeals from 150 feet away, or hear movement underground, dig, and capture their prey. From a distance, they creep low to the ground, slowly towards the correct location. Once they are close enough, they will often launch themselves up at an almost forty-five degree angle, pouncing down on the site of their prey. They can jump up to fifteen feet away! They will sometimes kill more than they can eat, and will bury food for future use.

Fox families have their own marked territories that they defend from intruders, a space that is from 150-400 acres. Scenting is an important form of staking territory, as they mark rocks and trees with their urine. When facing another fox, they may participate in a group chase or will charge and growl. They wave their tail to communicate their presence. Red foxes also have a wide range of vocalizations that peak during winter during the dispersal of juveniles as they stake out new ranges, and during the mating season. They have barks used as internal family communication, as a warning, or to convey information. They have “shrieks,” “staccato barks,” and “whines” to interact with others and establish contact. They have “wow-wow” barks for friendly communication. “Coughs” warn cubs of potential danger, and “growls” and “screams” are used in defensive positions.

If you seem me on the street, please do not be surprised if I give you a “wow-wow” bark as my hello. Also please know, if I cough, it is probably due to a cold, not a warning! Be sure to spend some of your own holiday season outdoors! Who knows what you will discover in your own back yard. Be sure to include a night listening session as well. For listening to potential fox sounds, choose cold, clear winter nights when fox prefer auditory communication. If you have your own red or gray fox story to share, please email the Museum at info@cablemuseum.org, or post your own stories on the Nature Watch blog at cablemuseumnaturewatch.blogspot.com.

For over 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Bird Coloration

2009-12-24T07:37:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

A blue jay darts across the yard. An American goldfinch shows its more camouflaged winter colors that are so drastically different than the summer yellow and black. Even the black and whit e of a chickadee against the snow is a striking color contrast. Color is not always what it seems in the bird world, in spite of the amazing variety of colors we see. Still, it seems to bring a gasp of pleasure when we see these colored wonders.

For most birds, color comes from pigment, which are chemical compounds located in the feathers or skin. Pigments absorb part of the white sunlight as it hits, and then reflect just part of the color spectrum, which is what the observer’s eye sees. For example, a cardinal has pigment that absorbs all the wavelengths of light except the ones that, when they enter our retina receptors, appear red. When we see black color, no light is reflected. When we see white color, all wavelengths are reflected. Melanin pigments produce blacks, browns, grays, and beige colored feathers. The pigments that produce yellows, reds, and oranges are called carotenoid pigments. These carotenoids are not produced within the bird’s body, however. Birds of these colors rely on their food – pink flamingos depend on carotenoid-rich crustaceans for their color, and the yellow goldfinches get their pigmentation from seeds they eat.
The blue of a jay that we see is not coloration based on pigments. In fact, blue and iridescent colors are "structural colors," produced in special cells in the feather barbs. For us to see “blue,” there are microscopic box-shaped cells that scatter the light, favoring the shorter blue wavelengths. Iridescent colors are produced by from modified barbules that cause wavelength changes based on the angle of reflection. These special cells split the sunlight, making iridescent colors dependent on the angle of the light. A ruby-throated hummingbird aligned just right makes a shimmering sight, but when turned wrong, the color goes black.
Many of our camouflaged birds exhibit what is known as "countershading.” These birds have dark backs with gradual lighter shading until the belly is white. Countershading tends to eliminate an abrupt shadow, absorbing bright light from above while reflecting light below where light is dim. “Disruptive coloration” is the use of patterns that break up the outline of the bird to avoid detection. Killdeers are an excellent example of this disruption, allowing the bird to blend in with the color of its background.
Why is coloration important? The earliest theory made by Darwin regarding bird coloration was that the bright coloration of males evolved through female choice of the most attractive male plumage. Another “color” theory is that bright colors can intimidate predators. Or, if we consider the bright coloration some species, such as monarch butterflies or coral snakes use to warn predators, it could be that the more colorful the bird the more unpalatable. It is believed that birds identify themselves to other flock members through color patterns visible in flight. Bright colors might help to deflect predator’s attention away from nesting sites. Colors inside of mouths of open chicks may stimulate parental feeding and help guide them to where “x marks the spot.” These are all interesting examples of how birds use their coloration.
Perhaps bird songs did not evolve for our human enjoyment, nor did bird colors evolve to delight our eyes. In spite of this, we benefit greatly from the joy they bring. Millions of dollars are spent every year as humans attempt to draw them closer to their homes. Birds are a part of many people’s regular conversation. We even bring their sounds and bright colors into our homes as pets. Whatever their color, they are an integral part of our human lives.
For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

What do they do for Christmas?

2009-12-17T07:52:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

While I watched students in a classroom writing their letters to Santa, I began to think about how different animals spend their Christmas. Where do the birds go? What about the frogs or turtles? Are the black bears already hibernating? What kind of “Christmas” do they have?

Where do some of the birds go for Christmas? For this answer, I had to go to my favorite bird field guides. The common loon leaves our lakes to enjoy the eastern and gulf coast, as well as the south-eastern part of the United States. Banded great blue herons from Canada have been found in Mexico, Honduras, Cuba, Colombia, Venezuela, and Ecuador’s Galapagos Islands. Some of my favorite forest-loving birds have just the right idea – red-eyed vireos end up in the western Amazon, hermit thrushes in the Bahamas, Guatemala, or El Salvador, and the black-throated green warbler in the Bahamas, Cuba, Jamaica, or Panama. The northern oriole heads to central Mexico or northern South America. Finally, the winter wren (how does it get that name anyway?) winters in the southern United States.

If we take a look at bald eagles of the Great Lakes region, they do not always migrate, though these resident eagles may travel significant distances in winter to seek food. Ruffed grouse stay with us, growing fringes on their toes in the winter to act like natural snowshoes and spending cold nights using the snow as insulation – imagine using the snow to stay warm. Next we can look at the resident bird that carries a bit of Christmas red color, the pileated woodpecker. These birds make deep, oval excavations in trees to find ants, especially carpenter ants, and wood-boring beetle larvae. These woodpeckers apparently have the “spirit of giving” year-round, as their large excavations often become feeding stations for other woodpeckers, wrens, or other birds.

Frogs have an interesting Christmas. Wood frogs, for example have no heartbeat. They do not breathe. Their blood does not circulate. Their nerves barely register electrical impulses. They are essentially frozen solid, yet their vital organs are not damaged. Spring peepers, gray tree frogs and upland chorus frogs also may freeze and thaw several times during the course of a winter. How do they do it? The answer is antifreeze. When ice begins to form on a wood frog’s skin, the frog’s liver releases a high level of blood sugar, enough to fill the blood vessels in all vital organs, creating a type of antifreeze. Other frogs will burrow into the soil or a lake bed to keep from freezing. Leopard frogs sink to the bottom of a water body, where they sometimes unfortunately become food for a fish.

Where do turtles go in the winter? All but one of Wisconsin's eleven turtle species spend Christmas under water. A few turtles bury themselves while others remain motionless on the bottom. Some scientists believe that they hibernate, their blood changing to function like antifreeze, with their body temperature dropping to only a few degrees above freezing. Other scientists believe that they don’t hibernate, but are semi-active, although this activity can take a toll on their body reserves.

When do black bears go into hibernation? Do they nestle in their beds for a long winter’s sleep? Technically, bears go into torpor, which is a state of reduced metabolism from which they can be awakened. Male black bears don’t always go into dens, sleeping right on the ground, or under downed treetops. These males can be more easily aroused from their “winter’s sleep.” When you add the fact that there are a lot of humans moving around in the forest during our fall hunting season, and combine it with the current feeding and baiting of deer or other animals, it is possible to see signs of bears even through November. The latest I have seen bear tracks in the snow is December 13, although most female black bears can go into torpor as early as October first.

As I wrap my presents, enjoy my lit tree, and huddle inside my warm house, waiting for a holiday season, I again find a renewed sense of wonder at the natural world. How fortunate we are to be able to enjoy this variety of wildlife all year round, no matter what the season or conditions in which we find ourselves.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Beavers

2009-12-10T07:59:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Some weeks seem like my best natural history observations are from a car. On my way back from teaching in South Shore School District, I kept observing signs of beavers in many of the wetlands along the way. Beavers are endowed with a series of very helpful skills that express their intelligence. Beavers are flexible, learn from observation, have imagination, an ability to plan, and can be innovative in their design. Generally, mammals rarely build structures, but beavers do far more than that. They build elaborate dams and canals to control water flow, create water levels that ensure the safety of their family, and make essential transportation pathways to find food and move building materials. In their “free time,” they build artificial islands and homes we call lodges. They are probably one of nature’s best architects!

Not only are they great builders and shapers, but at a rather large sixty or more pounds, beavers make their living while eating bark. Yum. Technically, beavers eat the ring of live tissue just under the bark. Located in this area is the phloem, containing water rich in sugars. Secondly is the xylem, the plumbing that carries mineral-rich water up from the roots. Between these two “transportation tubes” is the cambium, which is responsible for making new rings of xylem and phloem as it is needed. When they are finished eating, the leftover pile of indigestible bark chips is used as nesting material, and the leftover trunks and branches becomes their “lumber” for building.

Part of what makes this species so amazing is that no situation in their world is ever alike – they must solve each hydraulic problem before them, expressing tremendous creativity to make things work. First, they build dams as a defense from predators. To build their dams, they will often put logs in the bottom of the stream across the direction of flow, pile on more logs, use stones to hold it in place, and seal this foundation with extra sticks and packed mud. Other times they will fell one tree across the stream and use its mass to hold the water back. They will drive sharpened stakes into the stream bed. Scientists have observed an amazing array of techniques that beavers use to build their dams. The longest known dam is 2,200 feet! What a lot of work!

No matter how the dams are built, they are crucial when cold weather comes. A large pond that freezes over its entire surface can make breathing for an underwater mammal a big challenge. If the ice is thin, beavers can break open breathing holes, or can return to their burrows or lodges for air. What appears to be the best method of breathing, however, is that many beavers will cut a small channel through their dam. This allows the water to drain out just below the ice, where the gap between the water and ice provides a layer of air across the entire pond.

Next, transportation of beaver food creates a continual challenge, as we know that trees are heavy! When a beaver pond first runs out of trees close to the water’s edge, building a dam floods the area, providing more food. In time, though, they reach the point at which no more food is available. Beavers then begin excavating canals into the forest, cutting down trees along the edges, eating the tasty inner bark, and floating the branches back to the pond for use in future dams or lodges.

Another important feature beavers build is a lodge. Beavers seem to always understand what is needed, and come up with a strategy. For example, sometimes they will dig a burrow to live within, and other times will build a lodge. A family of beavers can include up to eight individuals. Their front door is in their floor, and this entrance must be at least a foot under water. The “bedroom” chamber must be above the water, and must be above the highest water level that could possibly occur throughout the year. Keeping safety in mind, they will even turn their lodges into island retreats by excavating a moat around them. Even on the coldest days, their lodge is built so well that it remains at a temperature above 40 degrees Fahrenheit.

Learning about beavers certainly puts my own life into perspective. When I complain about rising costs or the economy, or about the weather, or even the amount of energy I put into my job this week, it seems like I have nothing to complain about – my life is pretty cushy. Beavers work hard, and I sound rather lazy in comparison. On top of all the hard work they do, they coexist peaceably with many uninvited guests to their home, including muskrats, flying insects, mice, or water voles. If only I could do the same!

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Black Squirrel & Melanism

2009-11-30T09:23:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education

This week I was driving towards Winter School District to teach science and environmental education for the day, and thought to myself, “What is happening this week in the natural world that I should write about?” Not even thirty seconds later, a black squirrel ran across the road in front of me. I smiled as nature so quickly gave me an answer. What is it that causes these animal colorations?

The official word for this animal coloration is melanism. The black squirrels we see on occasion are really eastern gray squirrels with a genetic mutation. Melanism is an increased amount of black or nearly black pigmentation of skin, feathers or hair. Dark or even black squirrels or deer are said to be melanistic. These animals have too much pigment in their eyes, hair and skin, rather than too little. Biologists estimate that about one of every ten thousand squirrels has black coloration. Melanistic black squirrels can exist wherever gray squirrels live. Gray mating pairs may produce black offspring, and in areas with high concentrations of black squirrels, mixed litters can be found.

This black color phase in squirrels is not believed to be a genetic mistake, however. Before European settlers, it is reported that almost all squirrels in the northern states were black. Black fur absorbs more heat from the sun in our cold northern winters, and the coloration can be a defense in shaded, denser and dark forests. This darker color could have aided in hiding from predators of the sky. One scientist in particular, Dr. Bill Hamilton, suggests that as Europeans settled in this region, forests were cleared, farmland became a common use, and squirrels were hunted extensively as a food source and a perceived threat to farm crops. As this forest became more broken up, the black color was more easily seen, and so began to disappear from the population.

Black squirrels have gained great notoriety throughout the United States. Black squirrels have been introduced into one city to outcompete red squirrels. Some communities had black squirrels gifted to them, while another town has a legend that their populations came from a traveling circus. Some U.S. towns and one in Canada publicize with pride their black squirrel population. At least five colleges use the black squirrel as a symbol or mascot. Local residents in the Chicago area participated in a message board to share their own observations and “scientific” studies on the activities of their local black squirrel populations. Finally, in some alternative weather forecasting, black squirrel sightings are used to predict that devastatingly harsh winters are ahead. Let us hope that my sighting is not evidence that this type of winter is headed our way! In the mean time, enjoy looking for your own black squirrel nearby.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

White Tail Deer

2009-11-12T07:33:00.000-08:00

Nature Watch
By Susan Benson,
CNHM Director of Education
What can reach speeds of up to thirty miles per hour, can leap, and swim, and weigh up to 200 pounds? A white-tailed deer, of course. Mid-November appeals to us all for a variety of different reasons – the last days before winter sets in, the approach of a holiday of thanksgiving, or the approach of the deer hunting season. For me, it continues to be a deer appreciation time as their visibility increases through the next few weeks. White-tailed deer sometimes frustrate me as they chomp off my favorite flowers, but generally they are an animal I really enjoy. After all, how many other places are there where you can see such a large mammal every day of the year?
What interests so many is the obvious movement of deer as the rutting season for white-tailed deer reaches its peak - during the last two weeks of November and into December. Most of us know that bucks often pose themselves, hoping to impress their rivals and avoid physical contact. They may also engage in fights using their antlers and hooves. The fittest bucks, often having the largest racks, gain territory and become the fathers of next year's fawns. They often are the first to drop their antlers shortly after the rut.
Antlers are temporary projections, that although look solid, are honeycombed when observed through a microscope. During the spring, the lengthening of daylight signals more testosterone production, causing antler growth. Neck muscle develops to aid bucks with the additional weight of three to nine pounds. Does can occasionally grow antlers in times when they have a hormonal imbalance. During spring, deer browse heavily to replenish their fat reserves. Does use this energy for milk production, and bucks for antler production. Protein and minerals are necessary, although deer can draw from minerals they have deposited in their skeletons during other parts of the year. The deer also select plants with higher mineral content, and their stomachs can also change absorption rates of minerals.
Antler growth is linked to nutrition. Yearling bucks usually carry spikes, a single bone with no branching pattern, as their bodies focus on muscle and skeletal growth. However, older bucks can carry spikes when faced with poor food conditions. Bucks with higher nutrition can lead to larger antlers, as can genetic factors.
As their antlers grow, their fuzzy velvet supplies blood, and grows a half inch to one inch per day. By August or early September antlers are fully-grown, the bone dies, and the velvet dries and falls off. Contrary to common belief, bucks do not rub their antlers on saplings to remove the velvet, but most likely to strengthen their neck muscles to prepare for upcoming fights. Rubbing also helps relieve their aggression brought on by hormonal changes and communicates to others. Bucks rub their face as well, leaving behind a scent to advertise to other males and females. The duels that follow ensure that natural selection occurs – the strongest males pass along their genes. In addition to using their antlers for sparring, they use them for digging in early snows for food. Following the rut, amounts of testosterone decline and the bucks lose their antlers, usually in January-February, or for deer living in poorer quality habitat, even earlier.
I live among terrific deer habitat, surrounded by forest and agricultural fields, which makes for continual white-tail observations. I am familiar with the “flag” of their tail, perhaps meant as a warning, but to me is a hello and goodbye as they trot away from me across the field. This beautiful animal is just another good reason to live and hang out in the north woods.
For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Snow Bunting

2009-11-05T07:27:00.000-08:00

Nature Watch

By Susan Benson,
CNHM Director of Education

With the amount of snow we have seen in October, it seems only appropriate that the snow buntings have returned for their winter stay. We often see buntings darting away from the roadsides, similar to the juncos, but usually in larger flocks of up to 80 birds. With their white and tan colors, they blur in a flight that reminds us of a swirling snowstorm. These birds are of the Arctic, but we are fortunate to view them during our winters as they travel south.

Imagine flying south to winter in the north woods. While most migrating birds enjoy the southern United States or Central or South America, the snow bunting inhabits most of the northern parts of the United States and Canada. Buntings migrate this short distance to open habitats such as weedy or grassy fields, prairies, low mountains, sandy coastal areas, or sometimes cut-over farmland. Buntings are ground-feeders that feed on grass and other plant seeds from late fall to early spring, and seeds, buds, and insects in their breeding Arctic habitat.

As our winter transitions to spring, just like much of the bird world, the males use their coloration to attract the ladies. However, the snow bunting only has one molt each year, without the alternate plumage that we see on other birds such as the American goldfinch. After the summer molt, the male has the same white underside, brown patches on its face, with a brown and black striped back. Under their colored feather tips, the back feathers are black, and the body feathers are white. To prepare for spring, the male rubs off the brown feather tips in the snow so that he is a showy black and white by April.

These winter bunting visitors will be with us until April, when the males return to their high Arctic breeding grounds. The males move back to the tundra four to six weeks earlier than the females because of the fierce competition for territory. Their chosen nesting site – rock crevices – is a limited available habitat, so competition for the higher-quality nest sites is intense. Temperatures can still be down to -22 Fahrenheit, and food can be buried under snow, making the struggle to survive even greater. Snow buntings nesting choice provides benefits and disadvantages alike. In narrow rock cracks, the buntings have lower rates of nest predation, but it is also a very cold micro-climate for the young birds. To protect the eggs, buntings use a nest lining of feathers and fur to keep eggs and nestlings warm. Additionally, the females remain in the nest during incubation, to be fed continuously by the males. This extra parental care allows for a shorter incubation period and a higher reproductive success rate.

For those not familiar with this winter guest, it is worth pulling out the bird field guide to learn more about the appearance of this bird. When trying to view them in the area, look for those open habitats, mostly in what we would consider our agricultural areas. Be sure to bring a pair of binoculars along to enjoy this bird wonder!

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Tamaracks

2009-10-29T07:26:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Autumn Gold

The autumn gold colors of the tamaracks that greeted us this past week have been a joy to see. Although the tamarack tree resembles other evergreens, it is actually a deciduous conifer, so it sheds its needles every fall. It grows in cold, wet, poorly drained sites such as swamps, sphagnum bogs, and occasionally in upland soils. The pale green needles are soft, about one inch long, and grow in brush-like tufts along the twig. In the fall, just before the needles drop, they turn a beautiful golden color, providing a striking contrast to the last of the fall foliage.

Tamaracks have some other interesting characteristics. Their life expectancy is up to 180 years. They are cold tolerant and able to survive temperatures down to at least -85 Fahrenheit. The tree casts a light shade, so tends to have a dense undergrowth of shrubs with speckled alder, willows, red-osier dogwood, Labrador-tea, bog-rosemary, leatherleaf, or blueberries growing beneath. Because of its intolerance to shade, tamarack stands are usually even-aged.

The life cycle of a tamarack is appealing. In a bog, a tamarack tree is usually the pioneer, the first tree to establish itself in the sphagnum moss mat floating over the water.
It leafs off in the early spring before the ground has thawed, and takes four to six weeks for the needles to develop. In open areas, tamaracks can begin seed production when they are fifteen years old, but most pine cone crops come from trees that are 50 to 150 year old trees. One tree can produce as many as 20,000 cones in a good year, which can happen every three to six years. They can also produce root sprouts up to thirty feet from the parent tree. In mid-October the needles begin to change color. By the end of October, most of the seeds have dispersed, primarily through wind, but also by red squirrels forgotten caches. Most wind-dispersed seeds fall within two tree heights of the parent tree.

Animals interact closely with the tamarack tree. It is estimated that due to the consumption of seed off the ground, half of the crop is destroyed. Red squirrels cut and cache the cones for later eating. Mice, voles and shrews consume large numbers of seeds off the ground. Pine siskins and crossbills eat the seeds. By the time bacteria and fungi have “fed” off the seeds, it is thought that only about four to five percent of the seed that reaches the ground actually germinates. Additionally, snowshoe hares feed on twigs and bark, porcupines on inner bark. Ospreys sometimes choose to rest in dead tamarack, as do bald eagles on occasion.

Tamarack trees have an interesting natural and human history. Following the last ice age, it was one of the earliest species, along with spruce, to follow the retreating ice northward. Native Americans used the roots for cordage, the wood for arrow shafts, and the bark for medicine. Roots were used for sewing canoe edges. Early Americans used soft needles for stuffing pillows and mattresses. The wood was used widely for ship building, for timbers, planking, and to join the ribs to the deck timbers. The inner bark was used to treat melancholy, and the bark contains tannin that has been used for tanning leather.

Tamaracks seem to be sitting on the fence when it comes to deciding whether to be categorized as a conifer or a deciduous hardwood, and certainly cannot be called an “evergreen.” Regardless, we continue to benefit from their autumn beauty.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Dark-Eyed Juncos

2009-10-22T12:36:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Driving along the road this past week, I was greeted by the white flash of tail feathers from a quickly departing flock of birds from the roadway. Many of us have probably observed that each flock flies away from the road, and often lands back on the road behind us as we travel along. This spark of color belongs to the dark-eyed junco, one of the most common birds found in North America. For northern Wisconsin, a junco is a year-round resident, but juncos still migrate from Canada to disperse throughout much of North America during the winter. As they migrate, they are often observed scavenging seeds along the roadsides. The flash of color we see as they fly occurs as they pump their tail to show their white outer tail feathers. Their coloring mimics a winter scene with its dark gray above and snow white below. We can also enjoy these birds in other places as well, on woodland walks or at our bird feeders.

Juncos are primarily seed-eaters, feeding on many plants we might be familiar with – lamb’s quarters, chickweed, and sorrel, which make up three-quarters of their diet. They are one of the few bird species that usually prefer millet and cracked corn over sunflower seeds. In the spring, they often add insects such as caterpillars, beetles, moths, ants, and flies to their diet.

When foraging, dark-eyed juncos are seen hopping along the ground, scratching like a chicken at the leaf litter, or sometimes maneuvering successfully through low, tangled undergrowth to find food. During the summer males are very territorial, but in winter, they form large flocks of ten to thirty birds that can also include several other sparrows. Junco flocks have a “pecking order,” as early migrants have a higher status than later arrivals.

If you see a bird flock and are interested in identifying the dark-eyed junco or other species, grab a bird field guide and try to identify white-throated, white-crowned, chipping, or American tree sparrows. Also, don’t be surprised if what you first think is a junco or other sparrow is actually a yellow-rumped warbler, as they are one of the other last migrants to leave our area. Migrate yourself outdoors to discover what birds you can find!

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Goose Music

2009-10-15T09:35:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Goose Music

Almost daily it occurred this past week – the honk of a flight of geese in their migration flight, their voices in constant contact—what Aldo Leopold called “goose music.” Most flocks can number thirty to one hundred birds as they travel up to forty miles per hour at an altitude of 2,000 up to 30,000 feet. It is a sight everyone is used to seeing across the country and is a sound almost everyone knows. Canada geese are amazing birds that have been studied by scientists for many years.

Historically, it was a shock to many scientists to discover that many species migrated. Some naturalists felt it was impossible for tiny birds to fly so far without help. They conceived the idea that larger species, such as cranes, storks and geese, would carry these smaller birds as “living freight.” Some Native American tribes in the Western Hemisphere held beliefs that hummingbirds would ride on the backs of geese. Today, scientific study has taught us much about Canada geese and their success in migration.

Preparation for migration begins from the moment Canada geese hatch. Adult males begin molting right after mating, and the females begin five weeks after the goslings hatch. The adults re-grow their flight feathers and are ready to fly at about the same time as the goslings are able to learn - at nine weeks old. The parents teach them to fly, usually running along the surface of the water or ground for takeoff. As soon as the young are strong enough for the trip, the family begins their migration south. The young learn the migration routes from their parents and follow the same route in future years. Then the familiar v-shaped formation flight pattern begins.

Why do geese fly in a v-formation? Because it is hard to fly in an s-shape. Just kidding. In reality, the v-shape requires less energy, allowing the geese to fly longer distances. By flying slightly above the bird in front of them, there is a reduction in wind resistance. Geese can use fifty to seventy percent less energy due to the lead bird’s updraft. They can also travel at least seventy percent further than when flying alone. The larger, stronger birds are usually the leader. The lead birds rotate in a timely fashion to keep fatigue from occurring among the flight members. While flying in the v-formation, they can also communicate easier, and keep visual contact with each other.

Why are geese so loud when honking while in flight? It is believed that they are “cheerleading,” encouraging the leaders to keep up the good leadership, and to keep going! When they do travel, Canada geese stay in family groups. When ready to feed and rest, they land in familiar marshes or fields. When a large flock of geese comes in for a landing, family units “peel” off in smaller groups before they land. The next morning the arduous flight to central or southern United States continues.

It is amazing that geese, or any birds, continue to make the migration south with all the challenges they can face. When cloudy, birds may fly closer to the ground. They can have troubles with exhaustion from long flight with not enough rest. Bad weather such as snowstorms, thick fog, or strong winds can impact their success. Starvation from not enough food can occur. They can also fly into human obstructions or be shot by hunters. As we wish for their success in the coming days, we can continue to enjoy their goose music and flight overhead, soon to be a sound that will disappear until spring.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Bird Migration

2009-10-08T13:26:00.000-07:00

By Susan Benson,
CNHM Director of Education

It is estimated that as many as five billion birds migrate through the Americas every year. Approximately two-thirds of all North American bird species migrate. This means they travel from a breeding area to a wintering area and back again. They eat more food to gain fat for the flight. They molt old feathers, growing new ones. Many of these birds travel thousands of miles. They have no GPS or maps to navigate through the sky. The migration is timed so that young hatch as spring and fall berries and seeds ripen and insects arrive or decline. Finally, think of the ruby-throated hummingbird alone, whose weight is that of a penny, is about three inches in length, and makes a flight trek of thousands of miles while keeping a course through winds and weather. Bird migration is truly one of nature’s annual wonders.

Most scientists believe that birds navigate using the sun or stars as a compass. Some believe there is a chemical, a molecule called a superoxide, in birds’ eyes that allows them to sense the Earth’s magnetic lines as if there were a highway through the sky. Others believe the iron-rich magnetite crystals found in many birds’ brains allow them to detect the magnetic fields. Using visual landmarks, making mental maps, using olfactory cues, or genetic or environmental influences may also be amazing factors that help birds succeed with navigation and orientation.

Migrating birds generally move from north to south and from south to north. However, there are several birds that migrate over regular routes diagonally or even east to west before arrive at their destination. These diagonal travelers usually move only to the lower edge of their summer range in winter, travel east-west to a sea coast, or simply move to a lower altitude in the same place.

In late summer, before migration, the metabolism of migratory birds undergoes extreme changes. The actions of the hormones prolactin and corticosterone cause migratory birds to accumulate large amounts of fat under the skin. These accumulations provide energy for long flights.

Some birds migrate during the night to avoid predators and to eat and rest during the day. Nocturnal migrants will utter sharp and melodious peeping and piping calls, allowing individuals to stay in touch with each other.

Each bird creates behind it a small area of disturbed air during flight. Birds have learned to use this air to their advantage during migration. Air lost over the wing tips creates a spiral vortex behind each wing tip, with upswelling air on the outer side of each wing. Birds that migrate together fly aside or slightly above the bird in front and use less energy.

Migration is a very strenuous activity that requires extreme amounts of energy. Some birds will fly four to six days straight without any rest. Some researchers estimate that an equivalent feat would be similar for a human to run four-minute miles for a total of eighty hours!

We may never discover the scientific mysteries of the phenomenon of this annual cycle. Keeping a bird journal can help us learn a little more about our feathered friends. Record observations on a calendar and jot down some notes. Include any other observations of these birds. Perhaps you will discover a clue to solve the mystery of migration.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470

White Footed Mouse

2009-10-01T11:23:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Last night I had a guest over for dinner. She spent several hours, not creating much quality conversation. She dined mostly on chocolate, one of my favorite foods. Normally, though, she loves cherries, as she always leaves large piles of seeds behind when she goes. She was not one to sit for long periods, preferring constant movement, just like a young child squirming in her chair. I know this guest well, as she has been a regular visitor to my home for many years. I am always struck by her lovely brown hair with her big, brown eyes. As we sat watching a movie after dinner, I smiled at the behaviors of my regular visitor, the white-footed mouse. As she scurried back and forth in my living room, she was perhaps a bit rude to not spend more time sharing with me what her actions were. I woke up this morning, still pondering what she was doing while visiting the house, with plans, I’m sure, of becoming a permanent resident.

White-footed mice can be recognized by their rich, reddish brown fur, with a white belly and feet, and a tail almost half its entire body length. These mice are primarily nocturnal, solitary and are territorial, though their home ranges do overlap. White-footed mice climb and swim well. I can agree with this, as last night’s visitor was on the second story of my home, and I have been surprised in the past by watching these daring travelers climb walls in what seems like a single leap.

At home in our homes, white-footed mice also build their nests elsewhere in hollow trees, stumps, brush piles, old squirrels’ or birds' nests. Their nests contain leaves, grass, feathers, shredded bark or moss, silky milkweed fluff, and cloth or paper. Once they have moved in to our human “hollow tree,” they seldom travel more than 160 feet from their comfortable, cozy quarters. They have amazing homing instincts. Captured mice that were let go two miles away have found their way back to their capture site. White-footed mice cache or store a winter supply of food in the fall near their nests.

Having found many white-footed mouse caches in my own home throughout the years, I often wondered or searched to identify the source of the seeds. These mouse caches help store food for winter use, and have been reported to contain several quarts of food. Some of the foods they prefer include acorns, maple seeds, pine seeds, black cherries, jewelweed, blueberries, violet seeds, curly dock, and beechnuts. Like squirrels, white-footed mice have cheek pouches in which they can transport food. In spring and summer they feed on fruit, beetles, snails, centipedes, moths, grasshoppers, crickets, caterpillars, cocoons, and other insects. They occasionally eat small birds or mammals. They can feed on wood, bark, stems, fruit, and flowers. They also eat roots of plants and fungi. White-footed mice also help spread fungi by eating and eliminating the spores. This is important in aiding the ability of trees’ to take up nutrients with help of the "mycorrhizal" associations formed with these fungi. It is nice to know that in addition to the entertainment they provide in my home, they have such a beneficial relationship to trees.

The most interesting thing I found in researching this white-footed creature is a very distinctive behavior. White-footed mice, when sensing danger, will drum with their feet on a hollow reed, dry leaf or other resonating material, producing a prolonged musical buzzing. Perhaps my new quest should be to discover the drumming sound of the white-footed mouse. I actually searched online to see if I could find a recording. Although I failed in that search, I learned once again that there is something to appreciate in every one of the creatures in which we share our homes.

.For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

River Otters

2009-09-24T13:13:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

Questions about river otters have been coming into the Museum, as well as observations of them people have shared with Museum staff in local water bodies that. These sleek, muscular animals that I think of as the “teddy bears” of the water are regular residents of our area lakes. Calling a member of the weasel family a teddy bear might not quite be accurate, but every time I see one in the water I am delighted by their facial features and playful water antics.

The aquatic menu that otters select from is quite diverse and large. They will “munch” on small minnows, bass, sunfish, crayfish, frogs, or other aquatic animals. They forage in shallow waters along the banks, and will also eat birds or vegetation. Otters sleep and raise their young in dens such as empty burrows made by other animals, hollow logs, brush piles, or abandoned beaver lodges. Their home range is up to three miles.

During winter it is fun to observe their bounding tracks with their trail dragging between their legs, or their downhill slides towards the frozen lakes or bodies of water. Otters communicate by making sounds, like a bird chirping, a grunting sound when playing or grooming, and a high pitched scream when fighting or mating. When they get surprised or frightened, you may hear them snort.
Otters are known as playful animals. They like to wrestle, chase other otters, and play capture and release with live prey. Each of these "games" helps the otter become better coordinated and helps them fit into the social structure of the group. In the winter, you'll find otters traveling overland by bounding 3-4 times, pushing off with their hind feet, and then sliding 5-15 feet on the snow. Downhill slides are a bonus,

They are excellent swimmers and can stay underwater for up to 4 minutes. They've actually been known to dive to depths of more than 40 feet. Their speed and agility in the water helps them outmaneuver and catch fish and other quick prey. After about a year each otter will strike out on its own and establish its own territory.
All otters must continually groom their fur to maintain its insulating qualities. Otters spend a substantial amount of time grooming, and many species of river otters have designated areas on land for drying and grooming their fur. Most vigorously dry themselves by rolling on the ground or rubbing against logs or vegetation.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Fall Color Prediction

2009-09-21T13:09:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

What will the fall colors be like this month and next? I was contacted this week by Midwest Weekends travel guide to predict the fall colors for the Cable area. I felt a little nervous about making such a bold statement. My biggest fear was, “What if I’m wrong?” I decided to go out on a limb (yes, pun intended,) and make my prediction. It then became obvious around the Museum office that it had to be shared with the Nature Watch audience. So, will the colors be good this fall? Here is my prediction…

I predict that we could have a great fall color experience, and this is why. Here are the fall color basics. Three types of pigments are involved in autumn color. The first is chlorophyll, which gives leaves their basic green color. Chlorophyll is necessary for photosynthesis, the chemical reaction in which plants use the energy of sunlight to make sugars. The second pigment group, called carotenoids, produces yellow, orange, and brown colors. The last essential pigment, known as anthocyanin, produces red, purple, and crimson colors.

Both chlorophyll and carotenoids are present in leaves throughout the growing season. Most anthocyanins are produced only in autumn, in response to bright light and excess plant sugars within leaf cells. As the nights grow longer, chlorophyll production slows to a halt. Its green color fades from the leaves; the caroteniods and anthocyanins are then unmasked to show their colors.

The vibrancy of the colors is related to weather conditions that occur before and during the time when the chlorophyll in the leaves is dwindling. The series of warm, sunny days and cool, crisp but not freezing nights we have been experiencing seems to bring about the most spectacular color displays. During these days, a lot of sugars are produced. The cool nights and the gradual closing of veins leading from the leaf prevent these sugars from moving out. Lots of sugar and lots of light spur the production of the brilliant anthocyanin pigments.

The timing of the color change also varies by species. For example, oaks show their colors long after other species have already dropped their leaves. The differences in timing among species seems to be genetic, for a particular species at the same latitude will show the same coloration in high elevations at about the same time as it does in warmer lowlands.

Here is the unknown wild card. The amount of moisture in the soils also affects autumn colors. A late spring, or severe summer drought, which we have had, can delay the onset of fall color by a few weeks. They can also lower the intensity.

Perhaps it is only the optimist in me that thinks that the colors will be great, but regardless, we should all enjoy the experience. This is the best time of year to get outdoors, now that the insects are declining, and the trees colors greet us every where we go. Take a fall color tour. Attend the fall fest activities in many of our local communities. Go for a trek on one of our numerous hiking or biking trails. I hope to see you on the trail!

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Fall Migration

2009-09-10T08:26:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

We may still be hoping for summer, but the birds know better. Migration is peaking for many species, especially broad-wing hawks, Canada geese, and some of our nocturnal migrant warblers, flycatchers, vireos, hummingbirds and orioles. Barred owls and whippoorwills have been calling at night. Red-winged blackbirds and starlings are flocking in larger numbers. Keep your eyes out for these migratory treats.

Broad-wings can be seen passing through, with the right winds, in large numbers. Like most raptors, they are reluctant to cross large bodies of water. When they migrate south and encounter Lake Superior, the birds naturally veer southwest along the lakeshore. Broad-wings migrate at high altitudes and seldom stop to hunt during the days of their travels. Because of their dependence on cold-blooded terrestrial prey species, they migrate all the way to Central and even South America. In order to conserve energy on their long journey, they float upward on vertical air currents as high as they can go, and then shoot forward, coasting to the next thermal. These air currents, called thermals or updrafts, often are found above rock outcrops, buildings, or parking lots—surfaces that heat the air above them. When one broad-wing discovers a thermal or updraft, others quickly join it, all swirling upward in a “kettle.” Many different raptors use these same techniques for migration flight. However, these are just some of the fall migration clues at which to search for.

Warblers migrate at night in large flocks. As the full moon wanes after Labor Day weekend, look for bird silhouettes against the moon as they migrate. Anyone with a telescope with twenty to thirty times magnification can often see these birds on clear nights while “moonwatching.” Nocturnal migrants typically are birds that have longer distances to fly. Less wind allows for straight flight, so birds expend less energy correcting or maintaining their course in the air. Cooler nights provide benefits as nocturnal migrants maintain healthy body temperature without large water losses. The night cover also allows the birds to avoid predation. The right conditions can bring about good bird viewing during the next day.

A clear night with a slight, north wind can bring about good warbler viewing the following morning. During the fall, many males bright, spring breeding plumage has faded, but in spite of their paler reflection, they still have distinctive markings that can help with identification. To look for warblers, focus on mature woods, in clearings or edges of thicker forested areas. Wooded lakeshores also attract fall warbler species. Fall migrating warblers move in waves, in groups of mixed species. If a birder hears the “chick-a-dee-dee-dee” of a chickadee, it is a sign that warblers might be nearby, as chickadees often mix in with warbler groups during fall migration. Finally, knowing a little bit about their habitat can aid with identification. A bird foraging at eye-level could be a black-throated blue warbler, or a bird moving up and down a tree like a woodpecker could be a black-and-white warbler. Using these techniques makes it easier to catch a wave of warblers.

Nighthawks can be seen in the evenings in large numbers. These birds can be recognized by their long, thin wings marked with a white crescent near each tip. Adult males can be further identified by their white chin strap and white tail markings. Nighthawks migrate before cold weather settles in so they won't run out of flying insects that fuel their journey south. It’s amazing that these birds never seem to fly into each other as they dart this way and that for their food. They often time their flight with the air travel of flying ants. By mid-September, nighthawks will be gone from our area, and by late October they will be in South America.

Become a phenologist! Mark your calendar each day you see a change in the transition from summer to fall. After many years of recording, you can take pleasure in knowing when to expect an event in nature to happen.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Fruits of the Vine

2009-09-03T07:31:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

With field guides in hand, I stepped onto the dew-laden ground of the Forest Lodge Nature Trail. The sun was shining and the temperature of the late-summer day was warming up nicely. The late summer buzz of the cicadas greeted my ears. It was time to research plants on the trail in preparation of a Fruits of the Vine hike. I was greeted by a heavy-burdened cherry tree, and out the field guides came.

After some moments, I identified, for probably the second or third time (funny how the brain’s retrieval system doesn’t work as well as we age,) this plant as a cherry tree. I observed its alternate, oblong, lance-shaped leaves, and the ripening dark, purple fruit. I took a bite of a ripened berry, and puckered my lips at the bitter, sweet taste. Black cherry is not as highly valued as other cherries because of its taste, but historically has been made as tea made from the inner bark to help cure a variety of health problems. As I was standing near the tree, I noticed the yellow jacket, a wasp that during this time of year is commonly seen around our pop cans or sweet foods as it becomes more eager for food as our summer ends. Several other wasp species also appeared to be sampling the sugar-rich foods.

Chokecherries are another species I identified along the trail. This plant should not be ignored just because it has “choke” in its name. It has a sweeter taste than black cherries, is best harvested when it is ripe, and is eaten mostly as jelly. If you find a chokecherry, be aware that the less ripe fruits with a red tint have an astringent taste. The impact of this astringency causes a dry, puckering feel in your mouth that is caused by tannins. The tannins change the structure of our salivary proteins, causing a sandpaper feeling in our mouths. Astringency tastes unpleasant to many mammals, but birds do not have a “sense of astringency” and so eagerly eat these fruit. Raccoons, chipmunks and deer mice feast either on the fruit, or extract the round seed pit inside. Black bears will often pull chokecherry branches to the ground to strip the cherries right off the plants, damaging the tree in the process. This wild fruit makes a tasty juice, jam, jelly, or syrup for humans.

Other tasty treats to look for right now while out on the Trail or near your house include juneberries, raspberries or blackberries. Try eating American or beaked hazelnuts, or experience a milkweed pod that is about two-thirds grown, known to have a nice vegetable flavor. Be aware, though, that you are competing with squirrels, foxes, deer, ruffed grouse, turkey, woodpeckers, mice, insects, and deer for those delectable wild foods!

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Turkeys

2009-09-01T07:30:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

The day I saw my first badger was a highlight in my naturalist life, but was exciting for another reason. That same evening, I observed a turkey and four of its young crossing the road in front of me. Wild turkeys have been living in the vicinity of my house for a few years now and almost every summer I get the pleasure of seeing their large families. I continue to monitor in my phenology observation journal any observations, and I am keeping track of their success in this small northwest corner of the state. Successful restoration of wild turkeys has happened in Wisconsin, and it is surprising to see how well they seem to be doing in our region.

The turkeys around my house have plenty of food sources available to them. Bordering an active farm means the turkeys have access to corn and plant remains in cow manure. They can seek out unharvested crops, alfalfa, or grain waste. They also have access to native cherries, blackberries, raspberries, red elderberry, acorns, and seeds from the area’s maple, pine, spruce, balsam fir, and beech. Turkeys can also choose to eat catkins, buds, and leaves from the birch, hazelnut, ferns, strawberries, wintergreen, partridgeberry, clubmosses, trailing arbutus, bunchberry, and other ground-layer plants and grasses. There are plenty of grasshoppers, earthworms, grubs, leafhoppers, beetles, or crickets on which they can feed. These food sources meet the needs of what most Wisconsin turkeys seem to do well with: a fifty-fifty mix of oak woodland and agriculture. This is just part of their habitat, however.

Turkeys roost in trees overnight as protection from predators. Areas with dense cover keep them from wind or inclement weather. Trees with trunks about a minimum of twelve inches in diameter with horizontal branches are best, and in winter, turkeys will roost in conifers to better insulate them from cold weather. Denser understory vegetation provides safer nesting cover during the breeding season. Areas with insects or other protein sources are preferred breeding areas as turkey young eat one-fifth of their body weight each day. The home range of turkeys can vary from 135 to 500 acres depending on the time of year and availability of food and cover. Although turkeys are very adaptable, research suggests that they do better when food, roosting sites, and nesting sites are located close together.

Why do turkeys seem to be doing so well in northwestern Wisconsin? When outdoor temperatures go below 50 degrees Fahrenheit, a turkey’s metabolic rate speeds up, allowing them to survive colder temperatures only if they have enough food. Snow with a depth of more than twelve inches also hampers their walking ability and opportunities to find food. The northwestern part of our state has an average of forty to fifty days of twelve or more inches of snow, usually limiting turkey survival rates. Our recent warm winters must be contributing to their success.

Historically, turkeys were not documented except in the very southern parts of the state. In the 1970’s, turkeys were brought from Missouri to several sites throughout the southern part of the state, with more limited releases north of the ten-inch snow line. It is believed that the populations in this area are probably “immigrants” as those northern populations survived many of our warmer winters and dispersed into our area.

It is exciting to see the male turkeys showing their beautiful strut in the spring, or to see the young trailing behind their parent. I continue the search around my house for turkeys – their feathers, tracks, or observations I occasionally enjoy, and my next goal is to hear them gobble! If you have your own turkey story to share, please Email the Museum at info@cablemuseum.org.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Bird Flight

2009-09-01T07:27:00.000-07:00

Nature Watch
By Susan Benson,
CNHM Director of Education

The robins are back again. For the past two days, large numbers have been weighing down the trees in the Museum’s outdoor classroom. Robins flock together for feeding and for migration, so I imagine they are getting ready to instead of “raid the frig” they are ready to “raid” the mountain ash berries. Watching them flutter and fly is such an enjoyment. Have you ever wished you could be a bird for just one day, just to feel what it is like to fly? Bird flight is an amazing adaptation!

The wing of a bird consists of two functional parts: an inner part nearest the body and the outer hand. The outer hand, with its pliable flight feathers, functions as a propeller. The inner part provides the bird almost exclusively with lift.

All birds, except the hummingbird, move their wings at the shoulder, elbow and wrist. The entire hummingbird wing is a “hand wing,” or propeller. It does not soar or glide. Since the hummingbird moves its wings solely from the shoulders, it has great maneuverability in the air. The wing is extended throughout the whole stroke, making a figure eight and producing lift on both the up- and down-stroke. With this beat many hummingbirds can beat their wings fifty-two times a second.
Gliding is the simplest form of flight, when a bird’s wings make no propulsive movements. It is actually coasting “downhill” in reaction to air currents. Larger birds such as the albatross, condor, vulture, eagles and storks minimize their use of energy while gliding.
A soaring bird is one that maintains or even increases its altitude without flapping its wings. There are three main requirements to soar successfully: large size, light wing-loading, and maneuverability. Many birds that use soaring as a flight technique have deep slots in their wings to decrease drag and aid their take-offs.

Birds may stay aloft by riding rising warm air current called thermals, or by obstruction currents, which are updrafts of air caused when steady winds strike and rise over objects such as mountains, hills, buildings, and sand dunes.

Many birds hover by flapping their wings sufficiently to hold their position over one point on the ground. A hawk or kestrel does this by beating its wings, depressing and spreading its tail feathers, and holding its body at a nearly vertical position. They can hover for longer lengths of time by flying into a headwind, allowing them to stay stationary.

Much of our human flight was created through the intense observation of birds in flight. We learned from their streamlined bodies that help them overcome air-resistance. We discovered their hollow bird skeleton used to reduce weight, and the large keel of their breastbone. Most of all, they give us much entertainment and enjoyment.
For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Badgers

2009-08-13T13:07:00.000-07:00

Nature Watch

By Susan Benson,
CNHM Director of Education

It happened this week for the first time. I saw the animal I’ve been searching for in the north woods for over 23 years. This week while driving home, I saw an animal crossing the road in front of me at some distance. “Oooh, a larger mammal…what could it be?” I thought. My first thought: “it could be a fisher, but no, it couldn’t be because it isn’t bounding across the road like a weasel or squirrel.” My second thought: “maybe it is a gray fox. The color is about right, and the shorter legs seem to fit, but no, the movement doesn’t quite fit.” As I approached, to my astonishment, I discovered it was a badger. It lingered on the side of the road, turned and looked at me, and then loped off into the woods. I had been privately convinced that badgers could not live in northern Wisconsin because I hadn’t yet seen one, but there it was, finally, right in front of my eyes. I’ve rooted for the Badger Football Team, and celebrated the badger as our state animal, and finally I discovered that badgers DO really live here, and they are a resident of the Town of Cable!

Many are aware that we are called the “badger state,” but the actual reason for having that name is due to the miners in the 1800’s who dug tunnels into hillsides to search for lead, mimicking the badger as they lived in the tunnels during the winter to stay warm. The mammal we call a badger is usually not seen because like the miners, it spends its days inside its shallow den. These solitary animals hunt mostly at night so are not commonly seen.

What is badger habitat? Their habitat is made up of untilled fields or grasslands, pastures, hayfields, fence lines, roadsides, or prairie remnants, but can be at home in places that have two basic requirements: good prey availability and sandy soil for digging. Unlike Wisconsin “badger fans” who might prefer hot dogs, nachos or peanuts at a game, the badger eats rabbits, eggs, insects, snakes and small birds. However, since they live most of their lives underground, they will dig right into the burrows of other ground dwellers such as woodchucks and ground squirrels. Their sense of smell nearly matches the smell of dogs, animals that have one thousand times better sense of smell than humans, making it easy for badgers to scent their prey even underground.

What about their digging? Badger digging habits are impressive. A transparent membrane covers their eyes to protect them from the soil as they are excavating. Webbed front feet with efficient claws push out dirt effectively, and loose skin lets them turn in tight corners underground, or twist out of a predator’s grip. Their wedge-shaped head also moves through soil quickly, and lets them scent their prey. Badgers burrow through soil as a means of protection, and have been observed digging fast enough to dig their body out of sight within minutes. They spend at least ninety percent of the winter in their den, or “sett.” The soil around the den keeps the badger insulated, as the den can be up to thirty-one degrees warmer than the outside air.
How could we recognize a badger hole? Badgers dig horizontally into the sides of their tunnels, looking oval-shaped, and with many claw marks in the sides. Their tunnels can go twelve feet deep and be as much as fifty feet long.

Just how common are badgers in northwestern Wisconsin? In 1961 mammalogist H. Jackson used trapping numbers to predict that there were 5-20,000 badgers in the state. Since badgers are protected now from trapping, estimates are more difficult to make, but in 1975, a DNR wildlife biologist estimated the population was 8-10,000. A study in Illinois showed badgers moving as much as three miles in one night, and were found to have a territory of ten to twelve square miles. In Wisconsin, badgers have been recorded in every county except Milwaukee. In our area, Douglas and Bayfield County are in the top five counties for badger observations from 1987-1998.

At the end of the summer, it is more common to see badgers crossing roads, as the young are dispersing to new habitats and are in search of a new mate. After researching this mammal, I feel lucky to have finally seen one of these beautiful creatures. Keep your eyes out with hopes that you could make the same observation. Please Email your own badger observations or stories to info@cablemuseum.org.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

American Goldfinch

2009-08-06T13:04:00.000-07:00

Nature Watch

By Susan Benson,
CNHM Director of Education

Did you know that an American goldfinch pair has almost exactly the same flight call, making it easier to identify them? Or that they adhere to the strictest vegetarian diet, to eat insects only by accident? This week at the bird feeders, the goldfinches filled every feeder space filled on the sunflower seed feeders, striking in their bright yellow colors. It is a joy to see them, or to hear their song, “po-ta-to-chip, po-ta-to-chip” in a steady rhythm.

The American goldfinch is the only finch that is busy molting its feathers two times a year. The first time is in spring, when males display their bright yellow plumage to attract a mate, and then in late summer, as they begin losing their feathers again to become a more drab, olive color throughout fall and winter. The lemon yellow color comes from special carotenoid pigments given special names like zeoxanthin, leutin, and beta-carotene, which come from plant pigments the males consume. The beak is pink for most of the year, but bright orange in both sexes during the spring molt.

American goldfinches breed later than most North American birds, waiting until June or July. It is believed that this timing is better, when milkweed, thistle, and other plants have gone to seed. Goldfinches use these fluffy plant parts to line their nests and the parents also feed their young with the seeds. Spider webs connect the nest to its foundation, and when finished, the nest is no more than three inches tall or wide, and is so tightly woven it can hold water. Goldfinches provide a bird nesting environment that brown-headed cowbirds cannot survive well. Known for laying their eggs in other birds nest, cowbirds will hatch in goldfinch nests, but rarely live longer than three days, not being able to survive on the granivorous, all-seed diet fed to goldfinch young. Once the breeding season is over, goldfinches can be found in large flocks.

The American goldfinch feeds like an acrobat, using its feet to hang from seed-heads, reaching seeds more easily. In the spring a finch feeds on birch or alder catkins, pulling the catkin up with its beak and then holding the catkin still against a branch with its toes. They also feed on maple sap, berries, and tree buds, as well as asters, sunflowers, grasses, thistle, ragweed, dandelion, mullein, and goatsbeard. It will eat at bird feeders provided by humans, particularly in the winter months, preferring thistle or sunflower seed. Flocks of Goldfinches are traveling nomads, moving up to five miles each day from feeder to feeder or other food sources.

To encourage goldfinches into our own back yard, we can plant native composite plants, as well as native milkweed. Then we can have the pleasure of enjoying “our” own group of goldfinches, cleverly called a variety of collective nouns such as, a “007,” “charm,” “rush,” “treasury,” or “vein” of goldfinches. Perhaps that is better than being called a “murder of crows,” a “plump of wildfowl,” a “knot of toads,” or a “sounder of swines.” What will you discover in your own back yard in the coming week?
For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Bird Food

2009-07-30T12:59:00.000-07:00

By Susan Benson,
CNHM Director of Education

Earlier this spring, when school groups were visiting the Museum, white boards were set up outdoors to “feed” ants in order to teach about ant intelligence. After two days of feeding the ants, I noticed a robin, almost appearing as if it was trying to run me out of the area. The following day, there were significant scratch marks that were made by a small “implement” that I assume must have been the robin, having eaten the peanut butter. Every day thereafter, I saw the robin, and later, the peanut butter would be scraped clean. This morning after the rain, I was watching five robins in the Museum yard and began thinking about birds and their food.

Natural foods that birds eat include insects, worms, grubs, berries and other fruit, tree sap, buds of trees and shrubs, nectar, nuts and seeds, fish and small animals or other birds, eggs, or dead animals.

Sometimes it is surprising to discover what some birds eat. For example, ruby-throated hummingbirds feed on the nectar of mostly red or orange flowers. However, they will also catch insects in midair such as gnats, mosquitoes, fruit flies, or small bees. Hummers will also pull them out of spider webs, and sometimes eat the spider as well. Hummingbirds also take insects attracted to tree sap or pick small caterpillars and aphids from leaves. A red-winged blackbird is believed to eat a diet of up to fifty-seven percent plant seeds, twenty-six percent insects, thirteen percent grain.

Birds have high body temperatures and high metabolic rates so they eat more food ounce for ounce, in proportion to their weights, than do most other vertebrate animals. Larger birds generally eat less in proportion to their body weight than do smaller birds each day.

The smaller a bird is, the more time it needs to spend feeding. Eagles may go without food for several days without ill effect, but the tiny chickadee needs to feed regularly throughout the day in order to survive. The bird with the widest variety of diet ever recorded is the ruffed grouse. Its food is known to include 518 kinds of animals and 414 different plants.

Birds digest their food very quickly. Some small birds like the chickadee eat almost constantly, especially during the winter. Diurnal birds feed most heavily in the morning and late in the afternoon.

Clues can be taken about what a bird eats by observing the type of beak or bill the bird has. Thin, slender, pointed beaks such as those found in warblers are found mainly in insect eaters that use their beak to pick insects off leaves, twigs, and bark. Beaks which are flat and wide at the base are found in birds such as flycatchers, which catch insects in flight. These birds also often have whiskers at the corners of their beak which widens the mouth opening, allowing more successful capture of prey. Woodpeckers have a chisel like beak for pecking holes in trees. Mergansers, adapted for fish eating, have sharp tooth-like edges on the bill to hold fish tightly. The fringed edges of a mallard bill strain plants, seeds, and small animals from water. Cardinals, grosbeaks, finches, and sparrows have a thick, cone-shaped bill good for cracking seeds all year long. When seeds are scarce they eat insects.

Whatever birds may eat, they continue to be a source of enjoyment for humans. It is estimated that over sixty million people in the United States feed birds in their back yards. Birds play an important role in balancing healthy ecosystems, and certainly contribute to our human economy. Sadly, many people are not aware that ten percent of our 852 bird species of North America are endangered or threatened. It is impossible to imagine what our lives would be like without them.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Crows

2009-07-23T11:33:00.000-07:00

Nature Watch

By Susan Benson,
CNHM Director of Education

For the past two weeks, I have been greeted daily at home by a lone crow. This is a continued surprise to me, because crows are social birds, more often observed in groups than alone. Was it injured? Looking for food? A young crow? All were questions I asked. In fact, young crows often assist their parents in raising the young for several years. One crow family can contain up to fifteen individuals with youth from as many as five combined years. In the winter they gather together in very large groups to sleep in communal roosts. Crows are considered highly intelligent animals, known for their impressive counting skills and use of tools.
.
Experiments with captive common, or American crows have proven the birds have excellent puzzle-solving abilities, can count up to three or four, have good memories, and can quickly learn to equate certain sounds or symbols with food. Known to eat the shells of clams, mussels, and mollusks, crows have learned they can eat more easily by picking the shells up, flying with them to a greater height, and then dropping them to rocks below. Herring gulls and crows were seen practicing this technique at the same time, but while the gulls dropped the mollusks onto the mud, crows figured out quickly that aiming for a rock worked better.

Crows have other creative ways to find food. During spring in Norway and Sweden, fishermen make holes in the ice and drop their fishing lines into the water. Hooded crows have been seen flying in, picking up the line, and walking backward, pulling the line out of the hole until they expose the bait or hooked fish to eat. Crows on a remote Pacific island have learned how to use tools. The birds use long, specially chosen twigs to spear the plump grubs that hide deep beneath the bark of rotting logs. Crows will follow adult birds to identify where the nest and eggs are located. Observers have seen crows shaping a stick to place in a hole in a fence post to search for food. They work together in groups called mobs in order to get food.
Crows have a varied and evolved language more extensive than just the “caw” with which we are familiar. They also have the danger calls and a hollow, rattle greeting sound. They can mimic the sounds made by barred owls and other bird species, and they learn to associate noises with events, especially when the events relate to food.
While some might find the results of crow’s adaptability an annoyance because of how they interact with the human world, their resourcefulness can also be highly regarded. Please share any crow observations you have made by Emailing the Museum at info@cablemuseum.org.

For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.