Wednesday, June 29, 2011

The Nature of Seeing

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.

Thursday, June 16, 2011

Tick,Tick,Tick

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.

Thursday, June 9, 2011

Fledglings

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.

Thursday, June 2, 2011

Barren Strawberries

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.

Wednesday, May 25, 2011

Bloodroot

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.

Tuesday, May 17, 2011

Green

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.

Wednesday, May 11, 2011

Living in a tree house

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.

Wednesday, May 4, 2011

Phoebes

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.

Thursday, April 28, 2011

Spring Peepers

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.

Wednesday, April 20, 2011

Every Moment Matters

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.

Friday, April 8, 2011

Gray Jay

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.

Wednesday, March 30, 2011

Bald Eagle

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.

Thursday, March 24, 2011

Spring Music

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.

Wednesday, March 16, 2011

Spring has Sprung

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.

Thursday, March 10, 2011

Weasels

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.

Wednesday, March 2, 2011

Aquatic Wonders

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.

Wednesday, February 23, 2011

Pine grosbeak

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.

Thursday, February 17, 2011

Coyotes

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.

Wednesday, February 9, 2011

Not only found in the hall of the Library of Congress

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.

Thursday, February 3, 2011

White-breasted Nuthatches

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.

Wednesday, January 26, 2011

Goldenrod Gall

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.

Thursday, January 20, 2011

At the Feeder

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.

Wednesday, January 12, 2011

Where Do Birds Sleep

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.

Thursday, January 6, 2011

Blue Jay

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.