Wednesday, December 31, 2008

Snowy Owl Irruptions

Nature Watch
December 31, 2008

By Susan Benson,
CNHM Director of Education

This winter, snowy owls are being reported across Wisconsin in Ashland, Appleton, Horicon, Oshkosh, and Milwaukee. As early as the beginning of November, snowy owls were even seen in the Chicago area. Birders everywhere believe that an irruption is on its way to the northwoods and Midwest. It is comical to imagine an eruption of owls, but note that the word is irruption, not eruption. An irruption of owls is a rapid and irregular increase in numbers when there is a correlation to a crash in northern rodent populations. Owls move south out of their Arctic and Canadian homes, appearing across the northern tier of states. Scientists believe that they are forced to move southward in search of more abundant prey as the lemming and vole population declines.

One theory is that the lemming population is high during the snowy owl breeding season, followed by a crash in the late summer or early fall as the lemmings run out of food, driving these larger numbers of snowy owls farther south in search of food. Add to this the fact that other snowy owl food such as ducks, have also retreated south. Finally, the snow and ice get so deep it is more difficult for the owls to find anything to eat.

For some areas, such as the Great Plains, the snowy owl movements are regular, occurring every season in about the same numbers. In the Midwest, the movements are more cyclical, with only a few being observed one year and dozens the next. During an irruption year, some of the owls that make it this far south can be in poor shape, and there are many stories of humans saving and rehabilitating snowy owls.

Ornithologists suggest that snowy owl irruptions occur about once every four years, with bigger ones about every decade. Data in Illinois showed 59 owls during the winter of 1980/81 and 46 owls in the winter season of 1991/92.

As a birder or phenologist, keep your eyes open this winter for snowy owls favorite habitats. In the far northern tundra, they live in wind-swept, open plains. They seek out similar territory in this region – grassy, snow-covered meadows, fields, airports, or beaches. Snowy owls like to perch a little higher than ground level, so can be seen on fence posts or brush piles. If you see one, in the spirit of good birding ethics, please err on the side of caution by giving them plenty of room when viewing or photographing them.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, December 24, 2008

Animals in Winter

Nature Watch
December 24, 2008
By Susan Benson,CNHM Director of Education

There are worse things than living for days on end with 20 below temperatures, or 40 below windchills. I know it’s difficult to believe, but it’s true. Imagine this instead…

Arctic terns fly 11,000 miles from the north pole all the way to the South Pole.

Deer eat acorns, fungi, and grass in the winter. They browse on basswood, sugar maple, sumac and other trees and shrubs, and they prefer the pencil-sized woody parts of these plants. They also eat 10-12 pounds of this tasty browse per day. I’ll take a hot burger over a basswood stem any day.

Beavers remain active underneath the ice. Back in the fall they were dragging branches of their favorite trees into the water near their lodge. Throughout the winter they swim out their underwater entrance to reach their food cache. Even on the coldest days, their lodge is built so well that it remains at a temperature above 40 degrees Fahrenheit.

Birds just plain shiver in this weather. Continuously. Crows, ravens, chickadees and finches are just a few of the species that shiver consistently.

Many species that are non-colonial during the warmer months will come together and make communal nests during the winter time. Deer mice, meadow voles, and even squirrels are examples. More individuals huddled together create more body heat and also reduces the amount of surface area exposed to the cold.

Honey bees maintain their body temperature through the winter by clustering together in a ball to conserve heat. The bees achieve an average temperature of 64 degrees in the center of the ball and 50 degrees at the perimeter.

Skunks, woodchucks, bats, bears, frogs, turtles, snakes, and other hibernating or dormant animals breathe slowly and lie cold and stiff without eating anything for months.

The wooly bear caterpillar freezes. They produce a substance similar to the ethylene glycol used in automobile antifreeze to protect them from the cold. By midwinter, the amount of glycerol in an insect’s body can amount to 25 percent of its entire body weight.

Whales must migrate as the water freezes so they go to warmer water to have their babies and return with their babies once they have grown.

Finally, if we think we get cold in the winter, we must consider the wood frog. They freeze solid during the winter months. They have no heartbeat. They do not breathe. Their blood does not circulate. Their nerves barely register electrical impulses. Yet their vital organs are not damaged, even after being frozen solid for weeks on end. In the spring, they simply thaw out and hop away to carry on with their day.

So, when we are feeling chilly and tempted to exclaim “I’m freezing,” or “I’m moving south,” both comments I have used in the past few days, remember that there are animals out there that are actually freezing, or dealing with situations I would not trade for anything.

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.

Wednesday, December 10, 2008

White/Black Fur

Nature Watch
December 10, 2008

By Susan Benson,CNHM Director of Education

If the color black absorbs heat, why is a polar bear white? This is a question a student asked me this week when I was teaching science and outdoor education in an area school. 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!

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.

Wednesday, November 26, 2008

Trees

Nature Watch
November 26, 2008

By Susan Benson,
CNHM Director of Education

When leaves fall off deciduous trees in the fall, it’s tempting to think that the tree is headed for a barren and lifeless winter season. But take a closer look — winter branches are not lifeless, but are in fact full of the promise of spring, even through the coldest stretches of winter. At the tip of each branch is a tiny bud, within which are future leaves, stems and flowers — folded, compressed, and covered by a waterproof coating of modified leaves called bud scales.

Through most of the year, tree buds enclose and protect the delicate growing tips of twigs and branches. During the winter, these buds act as protective cocoons, often sealed with wax and packed with moist cottony hairs to prevent the embryonic tissues from drying out.

Just as summer leaves vary in color and form, so do tree buds. In fact, in the absence of leaves, buds provide a good way to identify trees in autumn and winter. Their arrangement, size, shape, color, and the number, kind and arrangement of bud scales provide identification clues.

Buds provide for more than just the tree. Many animals rely on buds as an important food source during the winter, and particularly in the spring when the buds begin to swell. However, no great harm is done when a few buds are eaten; on a typical tree fully half the buds will not open in the season following their formation. If a squirrel nibbles away two or three future branches from a mature oak, for example, the nearest surviving bud will simply open to fill the void. Trees can also produce extra buds in areas of severe injury.

If you’re good at identifying trees by their leaves, try learning the differences among tree buds this winter. A good way to start is by finding a tree you can identify by some other means, say by the creamy white bark of the white birch, or a few characteristically lobed leaves still clinging to a red oak. Focus on the four common species first – oak, maple, ash, beech, birch, and aspen. Once you’ve learned these buds, move on to more challenging trees. On your next walk through the woods, get up close and look at buds for the unique traits they have.

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 new facility in Cable at 13470 County Highway M or on the web at www.cablemuseum.org to learn more about exhibits and programs.


RED OAK
Oak buds have many scales, overlapping in a spiral pattern like shingles on a roof. The buds are usually clustered near the tips of branches, where they are arranged in spiral patterns around the circumference of the twig.

SUGAR MAPLE
Sugar maple buds have many scales arranged in staggered rows, the midpoint of one scale centered over the space between two lower scales. Sugar maple buds are brown and conical, resembling inverted ice cream cones but without the ice cream. \

ASPEN
Quaking aspens often feature a reddish-brown bud at the end of each twig, with smaller buds along the length of the twig. The buds can be slightly sticky to the touch, and have a glossy, varnished look.

WHITE
BIRCH
White birch buds are tear-shaped, narrow and flattish, with one bud at the tip of each twig. The buds can be tacky or gummy to the touch.

Wednesday, November 19, 2008

Birds in November

Nature Watch
November 19, 2008

By Susan Benson,
CNHM Director of Education

Each day that goes by, I wonder if I am taking my last bike ride along the Namakagon River – for the season, that is. Sunday I went again, and was surprised at the muted colors, and the silence of the Riverway except for the bubbling of the water. This was such a dramatic change from previous weeks. Gone was the belted kingfisher I had previously seen and heard chattering. No eagles flew above my head. The occasional chickadee or nuthatch was all that I heard. It is the time of year when we know that our part-time residents, the migratory birds, have left us behind for some time. We are left with and comforted by the presence of our solid, cheery residential bird populations.

Merely 16 days ago I was greeted along the Riverway by the loud rattling cry of the belted kingfisher as it hovered above the water on a perch, waiting to plunge in head first into the water for a fish meal. Kingfishers are also known to eat other aquatic invertebrates, insects and small vertebrates. This bird is noticeable by its striking, slate blue head, large white collar, a large blue band on the breast, and white underparts. Belted kingfishers are one of the few bird species in which the female is more brightly colored than the male. The territory that they defend against other kingfishers can be a streamside and riverbed that is just over a half mile long. Now our kingfisher friends have left us to migrate to the coast, streams and lakes in the southern United States, Mexico, Central America, or northern South America.

At the same time I am saddened to see our non-residents leave our community, I am comforted by our residents, such as the red-breasted nuthatch. Identified by its white eyebrow with a black stripe through its eye, a black top head, gray back, with reddish underparts, this bird is found commonly in coniferous and mixed conifer forests of our area. Most people enjoy watching them as they climb down trees head first, probing crevices in tree bark looking for insects or spiders, eating conifer seeds, or storing food for later use under bark, in holes, or in the ground. Fiercely aggressive during mating season, the red-breast will chase away nest hole competitors such as the wren, white-breasted nuthatch, or downy woodpecker. This behavior continues beyond nesting season towards predators or competitors. This nuthatch even applies sticky conifer resin to the entrance of its nest hole (the male places it outside the hole, and the female puts it around the inside) to again keep out what they see as their enemies.

Over 110 bird species divide their time between Wisconsin and Belize, and many other species that enjoy other southern climates during our winters. These well-traveled birds bring us great diversity and enjoyment. From warblers to eagles, from ducks to robins, birds are the wildlife we experience most often and part of what makes our area special. We cannot take their songs for granted. The same may be true of our local, human population of “snowbirds”. Best wishes to all those “birds” who leave us, if only for a short few months.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, November 12, 2008

Winter Coming

Nature Watch
November 2008

By Susan Benson,
CNHM Director of Education

The Ojibwe word for November is “guckudinogizis,” meaning “the month when it freezes.” By the middle of November, most of our northern lakes usually have ice (harder to believe this is likely this year,) and we’ll likely also experience our first bona fide snow storm. Since it’s in the forecast as I write this article, it could happen by the time it is published. The bike rides may be at an end for this season, although phonological observations will continue! Other November observations include:

Most insects and spiders are now hibernating. The honeybee is one of the only terrestrial insects that maintains its body temperature through the winter. Thousands of honeybees
cluster together in a ball to conserve heat. The bees achieve an average temperature of 64 degrees F in the center of the ball and 50 degrees F at the perimeter.

Female black bears will begin their long winter sleep as early as October 1. However, male black bears are rarely in their winter sleep until early December. Why? Male black
bears often do not sleep in dens, but actually sleep right on the ground or under downed trees. Because they are above ground, male black bears are easily aroused during hunting season.

By Nov. 29, we’ll be seeing just nine hours of daylight. Don’t despair. Winter stars take center stage in November’s night sky, so enjoy the night sky more often.

Do you make a mental or written note each year when the lake first freezes? Do you scan the skies for migrating birds each spring and fall? Do you record the first snowfall more than one inch? Share your observations with the Cable Natural History Museum by emailing us at info@cablemuseum.org, and we’ll include them in our phenology database. Please look at the interesting data below. And enjoy making your own observations!


First snowfall more than 1”
10/25/01 CABLE
11/12/00 CABLE
12/19/98 WASHBURN
11/16/98 MARENGO
11/10/98 DELTA
11/10/99 CABLE
10/22/99 ASHLAND
10/6/00 HAYWARD
11/7/00 CABLE
10/06/01 CABLE
10/25/01 HAYWARD
10/12/02 CABLE
9/29/03 CABLE

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, November 5, 2008

November Phendogy

Nature Watch
November 5, 2008

By Susan Benson,
CNHM Director of Education

As our lake effect snow falls this Monday morning, my bike is put away for the season. I went for a walk, thinking about how all the northwoods have prepared for the coming winter. There are some interesting things that occur in the animal world.

Ruffed grouse grow fringes on their toes in the winter that act like natural snowshoes. These feathery feet do not exist in the summer or in regions without snow. These “snowshoes” don’t really have flotation devices, though, so sometimes the grouse, who like to walk, will end up kind of tunneling their feet through the snow. Like the weasel, the ruffed grouse uses the snow for warmth by spending nights and parts of the day after having dived down into the snow.

Gray squirrels eat about 40 pounds of acorns each winter. They grow longer coats during the winter, and sometimes grow white ear tufts in winter. It is believed that these ear patches look like small patches of snow, while the remaining coloration matches tree bark better. Motionless, this animal would be more difficult to detect by their predators. Squirrels that live in places that don't get accumulating snow don't grow the white ear tufts.

Imagine carrying your house around with you everywhere you go. Snails do, of course. In the winter, snails and slugs burrow into moist marsh soil for the winter, living off the fat in their bodies. Many snails secrete lime that creates a protective door over their openings.

Thirteen-lined ground squirrels, animals we often call gophers, hibernate all winter long. They layer on a coat of fat in the fall, and then settle into their underground burrows from October through March. When hibernating, their breathing rate decreases from 100-200 breaths per minute to one breath every five minutes. Their body temperature cools to almost that of the surrounding air temperature.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, October 8, 2008

Fall Colors

Nature Watch
October 8, 2008

By Susan Benson,
CNHM Director of Education

Every autumn we revel in the beauty of the fall colors. The mixture of red, purple, orange and yellow is the result of chemical processes that take place in the tree as the seasons change from summer to winter. During the spring and summer the leaves have served as factories where most of the foods necessary for the tree's growth are manufactured. This foodmaking process takes place in the leaf in numerous cells containing chlorophyll, which gives the leaf its green color. This extraordinary chemical absorbs from sunlight the energy that is used in transforming carbon dioxide and water to carbohydrates, such as sugars and starch. Along with the green pigment are yellow to orange pigments, carotenes and xanthophyll pigments which, for example, give the orange color to a carrot. Most of the year these colors are masked by great amounts of green coloring.

Chlorophyll Breaks Down
In the fall, because of changes in the length of daylight and changes in temperature, the leaves stop their foodmaking process. The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible and give the leaves part of their fall splendor.

At the same time other chemical changes may occur, which form additional colors through the development of red anthocyanin pigments. Some mixtures give rise to the reddish and purplish fall colors of trees such as dogwoods and sumacs, while others give the sugar maple its brilliant orange.

The autumn foliage of some trees show only yellow colors. Others, like many oaks, display mostly browns. All these colors are due to the mixing of varying amounts of the chlorophyll residue and other pigments in the leaf during the fall season.

Other Changes Take Place
As the fall colors appear, other changes are taking place. At the point where the stem of the leaf is attached to the tree, a special layer of cells develops and gradually severs the tissues that support the leaf. At the same time, the tree seals the cut, so that when the leaf is finally blown off by the wind or falls from its own weight, it leaves behind a leaf sear. Most of the broad-leaved trees in the North shed their leaves in the fall. However, the dead brown leaves of the oaks and a few other species may stay on the tree until growth starts again in the spring. In the South, where the winters are mild, some of the broad-leaved trees are evergreen; the leaves stay on the trees during winter and keep their green color.

Weather Affects Color Intensity
Temperature, light, and water supply have an influence on the degree and the duration of fall color. Low temperatures above freezing will favor anthocyanin formation producing bright reds in maples. However, early frost will weaken the brilliant red color. Rainy and/or overcast days tend to increase the intensity of fall colors. The best time to enjoy the autumn color would be on a clear, dry, and cool (not freezing) day.

Enjoy the color; it only occurs for a brief period each fall.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, October 1, 2008

Fall Trees & Birds

Nature Watch
October 2008

By Susan Benson,
CNHM Director of Education

Are the pines dying? When did the hummers last leave the feeders? These are some of the questions that have filtered into the Museum in the last two weeks. Read on for more answers.

Using the term “evergreen” to describe our conifers is not quite right. It is normal for some needles on our area’s conifers to fall off the trees. This occurrence, called fall needle drop, is a loss of the oldest and innermost needles shed from our pines, spruce and fir. Some fear that this is a disease, insect, or other warning sign, but is natural this time of year. Pines shed their oldest needles in the fall, and white pines usually shed their needles every two years. Sometimes the needle drop occurs in a short period of time, rapidly browning and falling, and other years, it’s almost unnoticeable because the discoloration happens over a longer time period. Environmental stress conditions can also affect this event, as root stress from extended dry periods, excess soil moisture, or poorly drained soils can impact this phenomenon, creating a greater needle loss. By the end of the needle drop, the trees may look bare, having lost approximately a third of their needles, and if the current season’s needle growth was a good one, there can be a greater fall needle drop. The needles on the tips of the branches are the newest growth, and if they were brown, this would be a larger concern and indication that something might be wrong with a particular tree.

What is happening in the bird world? Yellow-rumped warblers and sparrows are still migrating through. Migrating raptors and geese are still observable as is the occasional thrush in the forest. The ruby-throated hummingbirds appear to be gone. As requested in a previous article, last day reports came into the Museum from several people: September 16, September, 13, September 13, September 15 - all observed in the Cable area. Another report from Cable shared the past three year’s data: 2006, September 9; 2007, September 8; 2008, September 13. Thanks to those who shared this information! Ruby-throats do not do well in temperatures below the mid-20s (F), so this, mixed with the photo-period (shortening day length,) sends them south. A larger contributing factor driving migration is when there is the greatest food abundance. Banding studies have shown that those we saw in mid-September were not necessarily the same individuals we saw throughout the summer. Stumpy and the others we may have named at our feeders (this name comes from one of the Cable bird reports) might already be gone. The number of birds migrating south could be double that of the spring migration with the addition of immature birds. The immature have no memory of past migrations, and so follow an urge to gain weight and fly; once their flight is established the first time, it is possible that this becomes the route that bird retraces throughout its life. Some recommendations for those of us who have hummingbird feeders are to keep them out two weeks past the last day sighted, just in case there is a later migrant looking for food. At the same time, it is suggested to not keep your feeders out in conditions where they might freeze.

Earlier in the week it was raining pine needles. Today the sun shines. Our glorious fall weather and events continue. Get outdoors and enjoy it more, and please email any unusual observations to info@cablemuseum.org.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Day in October

Nature Watch
October 15, 2008

By Susan Benson,
CNHM Director of Education

What do birds do on a rainy, overcast day in October? I found out this weekend on a bike ride. Almost every day this fall I have gotten outdoors on my bike for a ride along the Namakagon River. Last Sunday, the maples were at peak. This week the aspens were at peak. Today, the maple I’ve watched change colors daily, was barren of every single leaf. Each day I stop along the route some place to make new observations. During this week’s bike ride, I watched and heard two bald eagles, an adult and juvenile calling; heard their wing beats above my head; and watched the adult fly swiftly and impressively as it followed along the Riverway. Slate-colored juncos were madly darting after each other through the brush. Black-capped chickadees and white-breasted nuthatches were flitting about. White-throated sparrows and many warblers were also foraging along the river.

Earlier in the week I was astounded by the numbers of migrating robins. They were everywhere, flying through the river valley, but in many other places around the region as well. I stopped long enough to find their favorite places, and discovered a chokecherry tree that had been almost completely stripped of all berries – in its upper branches the fruit stalks were empty. It was evidence that as our ground chills in the fall, robins do adapt their diet away from earthworms and more towards berries.

Robins form loose flocks for both feeding and flying during migration. By traveling in greater numbers, they are more able to notice predators and warn the others. Another advantage of their large flocks is that some individuals who have more experience and familiarity with an area can show others feeding or roosting areas. Their migration is patchy, with individuals spread throughout a bigger range to ensure that they will not deplete available food sources. Robins migrate mostly during the day, although move occasionally at night. They can fly up to 36 miles per hour, so can accomplish up to 200 miles per day. Robins often move ahead of warm fronts, arriving just before or along with rainy weather. Mixing these high pressure systems with northwesterly winds are good conditions for migration.

Migrate yourself outdoors this coming week, and enjoy all that fall still has to offer!

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 new facility in Cable at 13470 County Highway M or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, September 24, 2008

Children Outside

Nature Watch
September 24, 2008

By Susan Benson,
CNHM Director of Education

Take A Child Outside Week is September 24-28 this year. This initiative is a program designed to help break down barriers that keep children from discovering the natural world. The goal is to help children across the country develop a better understanding and appreciation of the environment in which they live, while increasing their enthusiasm for its exploration.
If you are looking for a beautiful place to spend an afternoon, look no further than the Cable area to the Forest Lodge Nature Trail. There exists a loop of trails with a wonderful blend of northwoods habitat. The terrain is perfect for an afternoon stroll, and the trails range in length from 1.2 to 2 miles, making it enjoyable for any level of hiker. The trails are located on the right side of Garmisch Road, left off of County Highway M.

When you arrive at this little gem, the sun beats warmly across tall grasses and recent wildflowers (asters, yellow coneflower, and goldenrod) that border the first stretch of trail. Here, chipping sparrows fly up before your feet, the heady scent of sweet fern reaches your nose, and the soft hum of pines meets your ears. Further on, you will reach the cool shade of a hardwood forest. Here, migrating birds weave through the sturdy trees, and mischievous squirrels and chipmunks dance about the branches. The trail passes a bog, where labrador tea bursts from the deep sponge of sphagnum moss, a vital element of a bog. Tenacious tamarack trees erupt from the sphagnum; the needles of these unusual evergreens are turning yellow, soon to drop to the ground. If you look closely you may see the unique blooms of pitcher plants, the bright red of cranberries hiding along the trailside. As you travel away from the bog, hardwoods become interspersed with hemlocks, whose branches are covered in soft, flat needles. If you look down you will see the dark, shiny leaves of wintergreen, the springy shapes of club mosses, like little Christmas trees. Flanking the trail will be several species of ferns: the semi-circular whorl of leaves that make up maidenhair, the long brown spores trailing from interrupted, the hairy stems of lady, and the three-pronged branch of bracken fern. A little bit further, the hemlocks dominate, the sun filtering through them and patterning the forest floor with golden lace. On the last leg of this journey, the trail lightens as birches and aspens begin to replace the hemlocks. You then return to the open prairie, spreading out before the parking lot from which you came.

As you step back into your car, you will take home with you amazing images, chance encounters with wildlife, and the rich, full moments that compose time spent outdoors. So, go ahead: take an hour, or even an afternoon, and explore the fabulous habitats.
Take a child outside, or just enjoy it yourselves.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, September 17, 2008

Black Bear

Nature Watch
September 17, 2008

By Susan Benson,
CNHM Director of Education

Do you like to eat? Probably not as much as a bear does. The black bear is a full-time, professional eater. Except during winter hibernation and a couple weeks in the summer during mating season, a bear spends all its waking hours looking for and eating food. Calorie-rich acorns from oak trees also are a favorite food for black bears. In fact, bears have been known to trek up to 50 miles to acorn-rich areas, and remember these spots from year to year. During the fall, bears prepare for upcoming hibernation by going into food frenzy -- they eat constantly and may gain up to a third of their body weight. In the fall, a hungry black bear might pack in more than 20,000 calories per day -- compare that to the average human's daily intake of 2,000 - 2,500 calories!

Black bears often are nocturnal, but may be active during the day, with activity peaks during early morning and late afternoon. In December they enter a winter den, which is frequently in a site with heavy ground cover with gathered bedding material. Black bears, unlike some mammals, are not true hibernators. They are easily aroused from their winter dormancy. Dormant black bears have a decreased heart rate and respiration, but their body temperature declines very little. They remain dormant for up to four months during the year, even when the weather is mild.
When walking outdoors, look for smooth-barked trees, such as aspen or birch, that have distinct slashes made by the bear's claws as it climbed a tree. Sometimes bears will chew on pine, spruce and fir trees, ripping off strips of bark near the base of the tree. They eat the sticky pitch inside the bark and will leave vertical tooth marks with their front teeth. Bears also mark trees to identify their territory and breeding status by rubbing themselves on specific trees and clawing the tree as high as they can reach.

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 http://www.cablemuseum.org/ to learn more about exhibits and programs.

Wednesday, September 10, 2008

Wild Rice

Nature Watch
September 10, 2008

By Susan Benson,
CNHM Director of Education

One of the most important strands in the ecological web of northern lakes and streams is Zizania palustris, commonly known as wild rice. This plant is an annual aquatic grass whose nutritious seeds have long served as valuable food for waterfowl. Within its core range in Minnesota and northern Wisconsin, wild rice is eaten by mallards, blue-winged teal, wood ducks, ring-necked ducks and other species.

This important plant is more than food, however. Wild rice provides roosting and resting areas to adult waterfowl and protective cover for young birds. It also provides habitat for snails, insects and mammals, adding to the biological diversity of the wetlands where it is found.

Wild rice also helps maintain water quality by binding loose soils, tying up nutrients and slowing winds across shallow wetlands. These factors can increase water clarity and reduce algae blooms. Wildlife and water quality are not the only beneficiaries of wild rice, though — this plant has long been a staple food for Native Americans and early European explorers of the region. To the Ojibwa, the plant is called manoomin, a term derived from “Manitou,” meaning Great Spirit and “meenum,” meaning delicacy.

Wild rice flourishes best in shallow, flowing water such as rivers and flowages, and in lakes that have an inlet and outlet. The plant grows in a predictable pattern. Seeds lie dormant in the lake or river sediment through the winter, and then germinate in the spring. In late spring, the new plants grow upward, producing ribbon-like leaves that float on the water’s surface. Through the summer, shoots may reach a height of two to eight feet above water.

In August and September the seeds develop and mature and become ready for harvesting. To the Ojibwa, the August full moon is known as Rice Making Moon, signaling harvest and thanksgiving celebrations. Today’s wild rice harvest methods remain similar to those used for centuries. The ripe grain is harvested from canoes or small boats with the use of smooth, wooden sticks. Generally, two people rice as a team; one moves the canoe through the rice bed using a long push-pole while the other “knocks” the grain from the plant seed heads into the boat. The freshly harvested rice then needs to be finished, a process involving parching to loosen the grain hulls, then winnowing the rice. The end product is a grain low in fat but high in protein, fiber, vitamins and minerals, nutritionally superior to white rice, oats, wheat or rye.

Wild rice can be hurt by pollution, the wake from large boats, exotic species and other factors. As a result many historic rice beds have been lost. Especially damaging are changes in water levels; the lakes and rivers that support rice have often been dammed, and even small increases in water depth can destroy the plant’s habitat. Although wild rice has declined in abundance from historic levels, there is hope that this trend may be reversed. A growing effort is underway to manage and restore wild rice. Tribal, state, federal and private natural resource organizations and interested individuals are working to protect and promote this special resource.

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 43570 Kavanaugh Street or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.

Saturday, August 30, 2008

Winter Preparation

Nature Watch
August 30, 2008

By Susan Benson,
CNHM Director of Education


Have you noticed mallards and other ducks migrating? Or have you run into a chipmunk scurrying across the ground, cheeks bulging twice the width of its head with hazel nuts? Or your pet cat, dog, or rabbit beginning to grow a thicker coat as the days grow shorter?

It is only early September, but winter is coming, and animals have strategies for coping. Breeding has been timed so that offspring can grow and develop enough to survive their first winter. These young have time now to grow their first winter coat. Mothers who have lost weight when nursing now have time to improve their condition before winter.

Some animals leave the area through migration. Land animals have a more difficult time with migration because walking is much less efficient than flying. For those animals that stay, there are other options. Body size determines where the animals that stay end up spending the winter. A moose, for example, with its long legs, can walk through the deep snow, but smaller animals cannot, so they have to prepare to spend winter either under the snow or in areas with little or no snow. The big brown bat will soon begin searching for a winter habitat—that may be in an outbuilding or your attic. Keep a lookout for any of the signs of animal preparation for the coming cold season.
The trigger for the change in animal physiology and behavior is the photoperiod—the relative length of light and darkness during a given day. With the relative increase in darkness, many big mammals gain fat between their internal organs and under the skin. In preparation for their long winter sleep, or hibernation, woodchucks grow enormously fat toward the end of the summer. During autumn, black bears eat more than usual to gain body fat to sustain them through their winter “slumber.” Bears do not truly hibernate, but rather fall into a deep sleep from which they can awaken quickly. During late summer, a bear will eat five pounds of food per day in preparation for winter. Imagine eating five pounds of acorns! Northern small mammals gather so-called brown fat, which generates heat very effectively. Black bears and other hibernating animals maintain this same brown fat because it has the ability to dissipate stored energy as heat.
The fur of foxes, badgers and squirrels thickens to allow them to keep their body temperature constant during the cold weather. The snowshoe hare begins growing its white fur coat, beginning with its ears and tail; the total color conversion takes about 10 weeks. The short-tailed weasel also changes its fur coat to white with the exception of the black-tipped tail, which is thought to be an adaptation so that when the weasel is being chased, the pursuer will focus on black tail tip and miss catching the weasel.
White-tailed deer are affected as well; in late summer, a gland in their brains stimulates the reproductive organs. In bucks, hormones increase and the antlers harden and the velvet is shed. The period of hard antler lasts from early September to early February. We are familiar with bucks rubbing against saplings and smaller trees, removing the outer bark, and exposing the tree’s cambium underneath. The bucks then rub the cambium with their foreheads, where a scent gland is located, leaving a sign of their presence left behind for others to discover.
Some mammals, like squirrels, mice, and beavers, gather extra food in the fall and store it to eat later. Squirrels store their food, either in centralized heaps, or buried in the ground, sometimes with just one nut or acorn in each hole. Squirrels will cover their hiding place with care; these caches are usually found within 75 feet of where the squirrel found the nut or seed. When the snow cover thickens, the squirrel digs out the hiding places, and after having eaten some of the seeds, hides them again, this time closer to the snow surface. Some squirrels even store fungi in the branches of the trees. In a good fungus year, one might see dried and darkened mushrooms hanging on the lower branches of trees. During the late summer and fall, beavers also put food away, storing branches at the bottom of their ponds in preparation for winter.
Become a phenologist! Create your own backyard winter habitat by constructing a pile of logs, rocks or leaves—ideal winter lodging for mice, shrews, rabbits, toads, frogs or other small animals. Enjoy watching the outdoor action as our mammal neighbors harvest nature’s fall treats.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

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Wednesday, August 20, 2008

Glacial Erratics

Nature Watch
August 20, 2008

By Susan Benson,
CNHM Director of Education

On a stroll through the backwoods of northwest Wisconsin, you may come across an unusual sight — a large rock, perhaps sitting all by itself in a meadow or on the forest floor. There may be no other rocks in sight. How did this one get here? You’re probably looking at a glacial erratic, a piece of rock that may have been transported great distances by the ice sheets that covered the region long ago. One long-distance champion is an erratic composed of solid native copper, probably originating from the Lake Superior region along the Upper Peninsula of Michigan, that was moved by glacial ice more than 600 miles to southern Illinois.

Glacial erratics can be any size from small pebbles to huge boulders. Most of them appear worn and rounded, sometimes including beveled or faceted surfaces. During the course of their journey, the rocks were jostled against other erratics or scraped against underlying bedrock, rounding off corners and planing smooth surfaces. Glacial transport also fractured some boulders, resulting in sharper edges.

Transportation by glacial ice produced other unique features, the most easily observed of which are glacial striations, series of parallel lines or grooves gouged across the rock face or inscribed on the underlying bedrock surface. These glacial furrows were produced when an erratic, frozen firmly in slowly moving ice, scraped against another erratic or against the bedrock surface over which the glacier was moving. These glacial striations can be used to identify the direction of ice movement.

The composition of glacial erratics can reveal their point of origin and give clues about the direction of ice movement. For example, a string of erratics of similar composition might be observed across a broad region. These are referred to as “boulder trains,” series of erratics that originated from the same source. Boulder trains appear as long lines or fans of erratics extending outward from their source in the direction of ice flow.

On your next hike, keep your eyes open for glacial erratics. Each one has a story to tell!

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, August 6, 2008

Redwing Blackbirds

Nature Watch
August 6, 2008

By Susan Benson,
CNHM Director of Education

“Today is August first, and I woke up to the terrific “chatter” of what sounded like hundreds or thousands of birds. Were they starlings in my back yard? Robins? Then it hit me – the red-winged blackbirds were already congregating. For the past three years, I’ve seen these birds in large numbers, always in early August, ensconced in my large pines, singing merrily. Am I lucky enough to have my backyard on their migratory pathway? Is there some other reason? The curious scientist in me had to explore.”
– From my phenology journal

Fall migration in the northwoods for red-wings begins in mid-July as birds disperse from their nesting areas to form loose flocks. The numbers gradually build through August reaching peak abundance during September 10-25. During this period, roost flocks ranging up to 50,000 individuals can be observed. Most fall migrants have departed by early November with a few stragglers hanging around through December. Some of these roosts will also include other bird species such as European starlings. Here we are in the sweet summer heat and weather, and I’m saying a fond farewell to our red-winged blackbirds!

When next spring comes around, the male red-wing is often one of the first migrants to arrive in our area. The male fiercely defends his territory during the breeding season, spending more than a quarter of all daylight hours in territory defense. He keeps other males out of his territory and defends the nests from predators. Humans wearing a red jacket into a marsh in the spring, should not be surprised to be attached by this fierce defender. Birders have seen the males chase crows, great blue herons, deer, and other birds as well. When singing to defend their territory or to attract a female, the male fluffs the red decoration and half-spreads his wings to show off the red and look his best. The red-winged males can also have up to fifteen different females making nests in his territory. A high percentage of territorial males have more than one female but, up to one-half of the young in "his" nests do not belong to the territorial male, having been sired by neighboring males.

We can continue to enjoy this bird species, as the red-winged blackbird is possibly the most abundant bird in North America. If you have your own red-wing observations to share or other interesting observations, please email the Museum at info@cablemuseum.org.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, July 30, 2008

Ferns

Nature Watch
July 30, 2008

By Susan Benson,
CNHM Director of Education

Ferns are the living dinosaurs of the plant world. They dominated the earth 300 million years ago and evolved into thousands of different species, some of which are still are found in diverse habitats throughout the world.

Ferns are not flowering plants and therefore do not reproduce from seeds. Instead, ferns produce dustlike spores that drop to the ground and grow into small plants which in turn produce a fertile offspring, the sporophyte, that we know as a fern. Ferns also reproduce through their rhizomes, which spread widely underground.

Ferns prefer filtered sun or shade, protection from high winds, enough space to grow to maturity, and an undisturbed root environment. Ferns prefer slightly acidic soils with a high percentage of humus to aid in water retention and drainage.

Ferns have an interesting history reflected in folklore and legends. Fern “seeds” were thought to make one invisible. Whoever obtained these “seeds” was thought to be able to find buried treasure, understand the language of birds, and have the strength of forty men. Throughout history, they have been an important source of food, drugs, and fibers.

With the exception of some species of algae, bracken ferns are the most widespread plants in the world. They will grow in most soils and can be found in shady, moist habitats as well as dry, sunny areas. In order to protect themselves, bracken ferns produce bitter-tasting compounds that discourage animals and insects from eating them. Ferns also generate substances that may act as natural fungicides, preventing the plants from getting certain diseases.

A partial list of other delightful ferns to keep an eye out for in the region’s forests include, maiden-hair, ostrich, interrupted, and sensitive. Hope you enjoy the looking!

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, July 23, 2008

Fireflies

Nature Watch
July 23, 2008

By Susan Benson,
CNHM Director of Education

Most anyone who is asked would be able to share a memory of firefly experiences throughout their childhood. The topic has come up several times this past two weeks with Museum visitors, shortly after I observed my first fireflies for the summer season. Sometimes called lightning bugs, fireflies are neither flies nor bugs, but are beetles, the most numerous order of all insects. About 130 different species of firefly illuminate summer nights around the globe.

The telltale flash you see on a summer evening is made by male fireflies flashing patterns of light to attract females, who signal in response from perches in or near the ground. When the male sees the female’s flash he continues to signal and moves closer. Eventually, through a series of flashes, they find each other and mate. Although other insects can produce light, fireflies are the only insects that can flash their light on and off in distinct signals.

Each species of firefly sends different mating signals. For example, the male firefly of the species Photinus pyralis beams a single half-flash while flying upward. To our eyes, the flash looks like the letter “J” spelled out in the night air. The female responds with a single flash.

Another species, Photinus consumilis, signals his mate with a rapid succession of flashes. She responds with two beams. In general, males will not fly down to a female that sends the wrong species signal. However, some females of differing species have evolved the ability to mimic the response flashes of species other than their own. As the male flies down to a mimicking female, he may be captured and eaten.

Here’s a fun way to learn about local fireflies. Go outside at different times during the evening and watch for their twinkling signal. Gently catch the fireflies in a jar. Make sure that air is provided by punching holes in the container lid. Observe the flashing pattern, counting the number of flashes and recording how long they last and the time between flashes. Record your data for five minutes.

Next, return to your capture site and release the insects. Wait one hour and return to your site. Recapture fireflies and repeat your observations. If you notice a different flashing sequence, you probably have a different species. Happy firefly hunting!

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, July 16, 2008

Third week of July

Nature Watch
July 16, 2008

By Sue Benson
CNHM, Director of Education

What is new in the natural world this next week? In the bird world, watch around your house for the Eastern phoebe—gray-brown above, and white below, and often seen pumping its tail when perching— it has begun its second nesting brood. By now pheasants and ducks have hatched, and egrets and great blue herons will have fledged from their nests.

The first generation of monarch butterflies is appearing right now. Male katydids can be heard at night as they rub their legs over their rasped and ridged wings like a fiddle and bow as they call. They can be seen as they feed in oak, cherry, and maple trees. In the world of spiders, the young ones, called spiderlings, can be seen riding the wind to new homes by casting their long-spun threads into the air from tree tops.

Deer flies are now out in force. The adults are hardy, strong fliers; males feed on flower nectar, honeydew, plant juices, and other liquids. Deer fly females feed on the blood of many warmblooded animals, including humans. When they bite, you feel it! Deer flies do not have piercing/sucking mouthparts like mosquitoes. Instead, they bite a hole in your skin with their strong mandibles, put a little saliva-like material in the wound to keep the blood from clotting, and then lap up the blood with a sponge-like proboscis.
Wild raspberries are beginning to ripen. Wild bergamot, a lavender colored flower, will begin blooming. Queen Anne’s lace is a white flower, so called because the flower resembles lace. The tiny red flower in the center represents a blood droplet where Queen Anne pricked herself with a needle when she was making the lace. Watch for these flowers in sunny areas.

Become a phenologist! Plant your own butterfly garden, and see what comes for a visit. Turn on a night light and observe and record what flies in—try looking at different times during the summer to see different moth species.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, July 9, 2008

July

Nature Watch
July 9, 2008

By Susan Benson,
CNHM Director of Education

July is a great time for watching natural phenomena. Fireflies are now active, creating a flashing light that serves as a signal to potential mates. Each species of firefly can be distinguished by the amount of time between its flashes. Much more can be observed in forest, water, air and field.
Bald eagles can be seen fledging in late July, about 70 to 98 days after hatching. Before this even, the young have been practicing flapping for weeks before their first flight. IF one falls from the nest the parents usually feed it on the ground. The parents encourage the babies to fledge by flying around the nest carrying food. After fleding, they usually stay with their parents for six weeks, continually being fed during this time. The young watch their parents fish, but don’t learn to catch fish for quite a while. They begin “catching” carcasses on shoreline and then pick up dead fish floating in the water. The immature eagles won’t get the distinguishing white head until they are three to five years old.
Jug-o-rum, jug-o-rum – this is the call of the bullfrog. In July, bullfrogs can be heard wooing mates or defending territory with their deep, loud call. Male bullfrogs are territorial and defend their territory by calling out to warn intruders. If that doesn't work, a shoving match may commence. Smaller males that cannot compete with large males for territories have evolved a trick of hiding out near the large calling male, intercepting females on their way to the larger male. Females lay eggs in large, jelly-like masses that can measure a yard across.

Wintergreen is one of the last wildflowers to bloom. It features white, waxy flowers that hang like little bells beneath the leaves. The newer, light green leaves have a tasty wintergreen flavor; dried leaves can be steeped to make tea which some consider to be a good headache remedy.

Cattails shed thousands of silky seeds in late July. Cattails can also reproduce vegetatively through their extensive underground stems. Cattails are very important for many animals, providing a place for the red-winged blackbirds to nest and hide their young, a place for fish to hide under the water, and as a food source for muskrats and young ducklings.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Friday, July 4, 2008

It's Summer

Nature Watch
July 4, 2008

By Sue Benson,
CNHM, Director of Education

You may have noticed the monarch caterpillars on the milkweed, the just-fledged birds being brought into the feeder, and that dragonflies are everywhere. You might also be asking yourself, “What is that flower along the roadside? Why do some fireflies light up in the air and others on the ground? What are the things to watch for in nature right now?” The study of the annual recurrence of seasonal change is referred to as phenology. Summer is a great time to be on the look-out for these phenomena.

Start by looking for monarch caterpillars. They are more visible during this part of the season than any other time in the summer. The caterpillars feed only on milkweed plants and are immune to its natural toxins. These toxins give the caterpillars and adult monarch butterfly an unpleasant taste, which protects them from predation by birds or other creatures.
Dragonflies, the small rulers of the sky, are also abundant right now. The dragonfly life cycle consists of three stages – egg, nymph and adult. They begin their lives as a nymph living underwater, where they eat other aquatic creatures. In some species, this nymphal stage can last for as long as four years. When the nymph is completely grown and ready, it will crawl up the stem of a water plant and emerge, ready to change from an underwater predator into an aerial one. With almost a 360 degree field of vision and the ability to sight their insect prey up to 33 feet away, makes them a formidable predator. Adult dragonflies can live up to two months. They are also capable of flying speeds of 30 to 60 miles per hour and can travel up to 85 miles per day.
Another flying insect regularly active in the summer are fireflies. As young larvae, fireflies eat earthworms, snails and slugs – they actually sometimes follow a slime trail to the slug. After locating their meal they inject a fluid into their prey to immobilize and eventually digest it. As adults, each individual firefly species has a unique process for courtship. Flying males emit a pattern of flashes while in search of females on the ground. Females do not often fly, but respond to the males of their species with a similar flash pattern. Some females will mimic the mating flashes of another firefly species in order to prey upon the unexpected suitor.
A flash of color might also grab your attention as to what is blooming. Ox-eye daisies, a drought-loving flower common along the roadsides, are white with yellow centers. Orange and yellow hawkweed abounds, growing at least 10 inches tall, with a dandelion-like flower. It is said to have been given its name because people believed hawks would tear the plant apart and put its juice in their eyes to give them their superior vision. Keep an eye out for the bright pink fireweed and milkweed flowers and the yellow butter and eggs and bird’s foot trefoil.

Other neat things in nature to watch for include bass fingerlings moving in and out of wetland areas for food and cover, painted turtles hatching and evidence of raccoons having raided their nests, and the first cicadas buzzing. Wild blueberries are also usually ripening about this time. As soon as the sun sets, Saturn and Venus are close together in the western sky. Enjoy the “Once in a Blue Moon” opportunity as July has two full moons; the first on July 1 and the second on July 30.

Become a phenologist! It’s easy. The only prerequisite to participate is that you must live somewhere where there are bird songs and trees.



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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at www.cablemuseum.org to learn more about their exhibits and programs.

Wednesday, June 25, 2008

What Makes a Lake

Nature Watch
June 25, 2008

By Sue Benson,
Director of Education, CNHM


What Makes a Lake?

The natural history of Wisconsin is a story of water, with the main characters being the glaciers, lakes and rivers that shaped and are still shaping the land. In fact, the word “Wisconsin” means “gathering of the waters.” In addition to wetlands, rivers, streams, and 1,000 miles of Great Lakes shoreline, Wisconsin is home to more than 15,000 inland lakes.

What makes a lake?

A lake is a body of standing water that can be formed naturally (by melted glacial ice, naturally dammed rivers, or other natural processes) or by human actions (reservoirs or farm ponds). Lakes are a critical part of the environment, serving as the collection point for all of the water that falls in its watershed — the surrounding rivers, streams and land that drains water into the lake. Lakes also provide important habitat for countless plants and animals, and provide us with aesthetic beauty and recreational opportunities.

Though we may come up to our favorite lake summer after summer, lakes don’t last forever. They get old naturally over time, filling with sediments, nutrients, plants and algae. The process usually takes thousands of years, though different human activities can either delay or speed the process.

Near the shores of the lake grow reeds and cattails and floating mats of sedges. Slowly, generations of sedge-mats die and sink to the bottom of the lake and decompose. Given enough time, the lake becomes a cattail marsh or sphagnum peat bog, where eventually there is no open water left. The lake has transformed from an aquatic community to a wetland community and will eventually become a wet meadow or perhaps a black spruce forest growing on peat.

As you travel the back country of the northland, keep your eyes open for “old” lakes — grassy lowland areas or depressions that may still be wet and spongy and are less thickly wooded than the surrounding land.

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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at www.cablemuseum.org to learn more about their exhibits and programs.

Wednesday, June 18, 2008

Eggs Rule

Nature WatchJune 18, 2008
By Susan BensonCNHM Director of Education

Eggs Rule!

What is an egg rule? Is it the number of eggs we should have in the morning for breakfast? Maybe not, but there is an ecological concept called an egg rule that expresses that the average clutch size laid by songbirds and birds in several other orders that tends to increase as one moves north in latitude.

There are few natural objects more interesting than bird eggs. Birds lay hard-shelled eggs made mostly of calcium carbonate. The hard shell keeps an egg from dehydrating and allows parents to sit on the eggs during incubation. Although bird eggs are hard-shelled, they possess microscopic pores, which allow oxygen to pass into and carbon dioxide to exit the shell.

Eggs come in a variety of colors and patterns. Colored and speckled eggs are laid in areas where they need to be camouflaged. Blue or green eggs are laid by birds that nest in shady places such as trees or shrubs (robins). This makes them less visible in the dappled sunlight. White eggs are laid by birds nesting in cavities (owls, wood ducks,) thought to happen because the eggs are usually hidden from natural predators. Birds that lay white eggs in open nests hide the eggs because they begin to incubate with the laying of the first egg. Others such as ducks, geese and grebes cover their eggs with plants when leaving the nest. Patterned eggs blend in with grass or small stones and are laid by birds that nest on the ground (gulls, sandpipers).

The shape of the egg depends on where the bird nests. The most common shape for eggs is oval. Birds that lay their eggs on ledges need eggs with a pointed end so they will not roll off the ledge (vulture). Round eggs are generally laid by birds nesting in a protected area, such as a cavity (owl). Birds that lay many eggs typically have eggs that are pointed. This allows incubation of several eggs in a small area (bobwhite). The number of eggs laid varies by species from as few as one for a seabird to nearly 30 for the bobwhite. The bobwhite needs about 3-10 minutes to lay an egg, but the goose is reported to take 1-2 hours.

This time of year the Museum staff hears stories from visitors about bird eggs and their nests. I was startled myself this week to have scared my resident phoebe out of her nest. She had set up in the same spot under the eaves that she has been using for many years. Enjoy the nesting birds in 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 in Cable at 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, June 11, 2008

Mosquitoes

Nature Watch
June 20, 2008

By Sue Benson,
Director of Education, CNHM

Buzzzzzzz! This is a familiar and irritating sound heard around our ears this spring, one we have gotten less used to last year with the extremely dry conditions. As they fly around us, we slap them, shoo them, spray ourselves and in general try everything we can do to avoid them and their bites.

The intense itching and swelling is an allergic response to the mosquito's salivary secretions. Mosquitoes are attracted to carbon dioxide, perspiration, body odor, lactic acid, light and heat to find their hosts. Some fragrances and dark colors may attract some mosquitoes. The most efficient way of reducing numbers of mosquitoes in your yard is to try to remove standing water in discarded tires, bird baths, plant saucers, and even gutters and flat roofs.

Mosquitoes begin life in aquatic environments. The eggs are laid on the surface of the water or sometimes are laid in moist soil that will eventually be flooded. The larvae hatch within about 48 hours. A larva lives in the water and comes to the surface to breath and shed its skin four times, growing larger each time. During the fourth shed the larva changes into a pupa.

The pupal stage is spent resting; they do not feed but are capable of movement, responding to light changes, moving with a flip of their tails towards the bottom or protective areas. Some mosquito species spend about two days as a pupa in the summer, and the skin splits, allowing the adult mosquito to emerge.

There are many kinds of mosquitoes, preferring different habitat, behavior and source of blood. It takes about two weeks after water is available for adults to appear, and more than 60 percent of these adults will migrate up to 20 miles from their breeding habitat. Only the female mosquitoes are blood sucking (the blood meal obtains the protein necessary for the development of her eggs) while the males feed on nectar and other plant juices. In the summer they can sometimes go through their entire life cycle in one week. Adult females will live for three to six weeks and can take several blood meals during this time. Temperatures below 50 degrees F prevent mosquitoes from flying.

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. They invite you to visit their facility in Cable on 43570 Kavanaugh Street or at the website at www.cablemuseum.org to learn more about their exhibits and programs.

Wednesday, May 28, 2008

May Birds

Nature Watch
May 28, 2008

By Susan Benson,
CNHM Director of Education
This past week has been enjoyable, watching the indigo buntings feeding at the bird feeders. The male, a brilliant blue while the female is a duller brown, migrates at night, using the stars as guidance. Scientists believe they gain knowledge of the night sky from their experience as a young bird observing the stars. They’re so good at navigation, in fact, that experienced adults have been known to return to their previous breeding sites even after being held captive and released away from their normal wintering sites.
Indigo buntings prefer brush along woods, roads or in open deciduous forests and old fields. They eat small insects, spiders, seeds and berries, and glean their insects off branches. When nesting, they create a open cup nest in shrubs close to the ground, and held in pace with spider webs. Their songs are a sequence of notes that are similar between males when they are close by; if the males are separated by more distance, they will have different songs.
Another favorite bird I listen for every spring is an ovenbird. Ovenbirds are rarely seen, but often heard. Their loud song, “teacher, teacher, teacher,” rings throughout the forests of our area. They are perhaps more well-known to birders because the neighboring males sing together in the spring; one male begins singing and others will join in after, sometimes for as many as forty different songs. The ovenbird is an interior forest warbler species that nests on the ground of mixed deciduous or coniferous forests. Ovenbirds get their name from their nest; they use Pennsylvania sedges that curl over, making a dome that resembles a Dutch oven. They focus on uplands or sloped area habitat, leaving the steep slopes and lower elevated areas for other warblers. Ovenbirds feed on insects off leaf litter on the forest floor.
Large forest areas are important to the Ovenbird, as they can require 30 to 250 acres to sustain populations. The Ovenbird is considered to be one of the most fragmentation-sensitive birds in the northeast, possible because the bird is a ground nester, making it more vulnerable to predators. Fragmented forests allow more predators into the forest, negatively affecting ground nesters. Studies estimate that only half of adult ovenbirds survive each year. This knowledge makes listening to the sound of ovenbirds even more special. Enjoy the songs of our forest bird species on your next trip outdoors.
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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Wednesday, May 21, 2008

Ephemerals

Nature Watch
May 21, 2008

By Susan Benson,
CNHM Director of Education

Locals like to call the time between when the snow melts and when the trees leaf out “mud season,” and with good reason. We may have had a short mud season this spring, but get out into the woods to discover a flowering spring treat: ephemerals.

Spring ephemerals are short-lived wildflowers that take advantage of a narrow window of opportunity when the sun rises higher in the sky and stays out longer, but before trees completely leaf out and block sunlight from reaching the forest floor. These opportunistic flowers will sprout, flower, wither and die back all in the space of about a week.

Often the first wildflower noticed by casual walkers is the trillium, a plant belonging to the lily family that has a large, often white, three-petaled flower above three broad bracts that look like leaves. These white flowers slowly turn into a shade of purple in the middle of spring.

Another ephemeral is hepatica, named from its leaves, which, like the human liver have three lobes. As part of the doctrine of signatures, it was once believed that plants were created for the use of human beings and as such, each plant displayed a signature of the purpose for which it was created - hepatica was thought an effective treatment for liver disorders. In marshy areas, look for skunk cabbage, a strong-smelling plant that Henry David Thoreau once called the “hermit of the bog.” Other spring wildflowers include spring anemone, spring beauty, wild geranium, marsh marigold, and bloodroot.

Being among the very first plants to grow and on the drab forest floor, spring ephemerals’ flowers stand out and attract pollinators like bees. Ants also play a role in the life cycle of these plants; after flowering, the spring ephemerals typically produce a small black seed with an energy-rich sac attached to it. Seeking food, ants gather the sacs and carry them to underground nests, leaving behind the seeds underground in their “garbage pile”, and essentially planting the seeds.

Watch for the flowers of spring ephemerals on woodland spring hikes, but avoid picking the flowers or digging up the plants, which are often rare or fragile and play an important role in the woodland ecosystem. If you are looking for some great places to hike and find spring ephemerals, try out the Forest Lodge Nature Trail, 9 miles east of Cable on Garmisch Road.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Tuesday, May 13, 2008

Spring Birds

Nature Watch
May 13, 2008

By Susan Benson,
CNHM Director of Education

If you have bird feeders at home, this past week you might have found the songbirds “eating you out of house and home.” My parents are feeding at least a pound of bird seed a day. There are many species of birds at my parents’ bird feeders, and almost daily my mother lists off to me the birds she’s seen. Here’s a list of returned migrants and year-round resident birds list from one day this past week: song sparrows, white-throated sparrows, white-crowned sparrow, chipping sparrow, downy woodpecker, hairy woodpecker, mourning dove, purple grackles, slate-colored junco, Eastern towhee, chickadees, blue jays, American goldfinch, American robin, ruby-throated hummingbird (yes-they’re back!), red-bellied woodpecker, purple finches, cardinal, red-winged blackbird, evening grosbeaks, rose-breasted grosbeaks, Baltimore oriole, brown-headed cowbird, and red-breasted nuthatch. Species seen in their yard include a catbird, house wren, flicker and yellow-bellied sapsucker. Other species visiting include chipmunk, red and gray squirrel, cottontail rabbit and white-tailed deer. The striking blend of colors is a continued pleasure to the eye.

The particular species that caused me excitement while feeder watching this week included the rose-breasted grosbeak, evening grosbeak, and Baltimore oriole. Go outdoors and listen for the rich, warbling song of a rose-breasted grosbeak, sounding a bit like a robin that has taken singing lessons. These birds prefer to nest in deciduous woodlands, especially at the edges. They eat seeds, fruits, buds and insects. The nest, an open cup of sticks, twigs, grasses, decayed leaves, or weed stems, is lined with fine twigs, roots or hairs that they place in trees or shrubs. The nest of this grosbeak is so thinly constructed that the eggs can sometimes be seen from below through the nest. The male spends about 1/3 of its day participating in the incubation of the eggs. When you hear the male, it probably means it is near or actually on the nest.

The large, stocky finch with a bright yellow back, rump and underparts, is the evening grosbeak. Their song, a series of short, musical whistles, appears not to be used in the functions of mate attraction and territory defense. Evening grosbeaks nest in coniferous forests, built mostly by the female and constructed loosely from sticks, moss, lichen and rootlets. The inside can be lined with grasses, roots, lichens, hair and plant fibers. Evening grosbeaks feed on a wide variety of natural foods such as seeds (especially maples,) small fruits, insects and other invertebrates. Some years you may see flocks at feeders, while in other years they stay further north and are not seen in their winter range. Results from the Christmas Bird Count show that the evening grosbeak is an irruptive species across much of North America. Long-term research shows that these birds exhibit a biennial pattern of irruption; plentiful years followed by years when low numbers are reported.

I squealed with delight this week at the arrival of the brilliant orange and black Baltimore oriole. This bird received its name from the fact that the male's colors resemble those on the coat-of-arms of Lord Baltimore, after whom the city of Baltimore, Maryland is named. Young male Baltimore orioles do not have adult plumage until the fall of their second year. In spite of this, some first-year males with female-like plumage succeed in attracting a mate. The orioles appetite consist of caterpillars, fruits, spiders, and nectar. Their gourd-shaped nest is hung from the thin branches or a fork in a tall tree, and is woven from hair and plant fibers. In our backyards, they can be enticed to visit feeders with oranges, nectars, grape jelly, or peanut butter. Most feeders are orange, as orioles probably recognize the color orange from afar, matching their own plumage; if they spot the bright orange color of an oriole feeder, they usually drop down to investigate.
While watching the orioles feed on oranges and grape jelly this past weekend, I started wondering: like many humans, can birds have a food allergy to jelly containing high fructose corn syrup? I looked to our regional bird expert, Laura Erickson’s birding blog, where participants recommended feeding only small amounts of natural grape jelly, real grapes, or grapes mashed in with jelly. One birder shared the following from Kent Mahaffey, manager of the San Diego Wild Animal Park: “Natural nectars contain 12% to 30% sugars, while jams and jellies are more than half sugar…We do our best for them when we stick as closely as possible to their natural diets.” Could it be that we need to shop at the nearest health food store for our birds as well?

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Sunday, May 11, 2008

Migratory Birds

Nature Watch
May 11, 2008
By Susan Benson,CNHM Director of Education

Wood thrush or American redstarts; they might be just one bird species, but they both share two habitats. How amazing that the same individual bird that returns to our yard each spring spent the winter further south. Many neotropical migratory birds breed in North America and spend our “winter” in Central or South America.

Over the years, land in North and South America has changed dramatically due to human land uses. Current human population pressures in Central and South America force people to clear forested land for homes, fuel, and agriculture. In these tropical habitats, bird migrants compete with resident birds for smaller habitat areas. These migratory birds might also be hunted for food or removed as pests of agriculture.

In the U.S. there is more forest cover now than at the turn of the century, but the forests are fragmented into smaller parcels, affecting habitat quality for wildlife that depends on interior forest conditions. Even small roads, running through a forest, fragment it and affect forest interior ground nesters. Nest predators such as brown-headed cowbirds, blue jays, raccoons, and feral cats gain access to songbird nests in these smaller forested areas. Wood thrushes and American redstarts are two birds that although present in the northwoods, can be affected by fragmented forests.

Wood thrushes forage for food on the ground, picking up insects and the occasional berry. Female wood thrushes build their nests in deciduous forests as low as six feet off the ground in tree branches.

Although it is a very common species of Eastern forests, the wood thrush is of high conservation concern because of steady, long-term population declines throughout its range for many reasons. According to the Cornell Lab of Ornithology's Bird Population Studies, this species has declined 43% since 1966. Declines in wood thrush populations have been linked to acid rain and forest fragmentation. This species seems dependent on large tracts of mature forest in some parts of its range, but is tolerant of disturbance in other areas. In a study done by Hoover (1995,) he found a 12% nesting success in a 22 acre forest while there was a 72% success rate in a 300 acre forest. In winter, wood thrushes are vulnerable to deforestation in the lowlands of Central America. The brown-headed cowbird frequently parasitizes wood thrush nests. In some parts of the Midwest all of the Wood Thrush nests contain at least one cowbird egg, and some may contain up to eight.
American redstarts hover while gleaning foliage, flushing out the hiding insects. They move rapidly while foraging, flashing their wings and tail to flush insect prey. They prefer second growth deciduous forests that contain abundant shrubs. Nest sites are located at the crotch of a branch from the main trunk of a tree. Nests are placed from 3-45 feet above the ground. They winter in the southern United States, Mexico, Central and South America. Declines have been seen in some areas, but the species is still widespread and abundant. Cowbird parasitism has been reported at 20% for this species.
While birding around the house this spring, enjoy these bird species. Listen for the flute-like sounds of the wood thrush or the varied musical see notes of the redstart.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Tuesday, May 6, 2008

Spring

Nature Watch
May 6, 2008

By Susan Benson, CNHM Director of Education

Could we have had a record snowfall in April this year? It surely felt like it, and let us hope that the snow is behind us, as May is perhaps the most exciting month for regional phenologists. Many northern Wisconsin bird species have returned and some of the later species such as warblers and shorebirds are on their way, either to develop territories here or rest briefly before heading to final destinations farther north. May forests are full of bird songs, most of them sung by males. In most cases, the males will stake out a territory and use their call to attract a female of that species to them. By now it’s likely that sandhill cranes have built a nest near open water in a grassy area. The fuzzy yellow-brown chicks are born within 30 days so should be hatching in mid-May. White-throated sparrow, tree sparrows, and song sparrows have arrived. May 7-15 is when Museum phenologists have recorded hummingbirds as having returned to this area.

Listen in the evening for the male American woodcock, which has the most elaborate display to attract females. One of my most favorite spring activities is to sneak up close enough to observe this ritual. The male gives repeated "peents" on the ground, stomps his feet, dips his bill, and then turns and repeats the sound and motion in several directions. After several buzzes the woodcock leaps into the air. As he gets higher, his wings begin to whistle using his outer primary wing feathers; he continues to climb in wide spirals until he's almost out of sight. He comes down in a zig-zag, diving fashion, chirping as he goes. After landing he buzzes again, and if he's lucky a female joins him. Males repeat this performance up to twenty times during an evening.

During some years (that have less April snow), a few species of flowers have already bloomed during April, while others make their first appearance in May. Dandelions are among the first plants to pop up in the spring, and I have observed them blooming in Ashland. Species such as hepatica and bloodroot should be blooming soon; other species such as starflower, trillium, lilac, blue-bead lily, Canada mayflower, forget-me-nots and marsh marigold will be seen during the coming weeks.

Keep your eyes out in the forest for one of my favorite signs of spring, the blooming leatherwood, a woody shrub that grows up to 8 feet, but is usually smaller. The small, yellow bell flowers are delicate and beautiful. As its name suggests, the stems are soft, leathery and very pliable, yet still very strong; the stems can actually be tied into knots. The bark is fibrous and can be peeled off in strips and woven into twine.

Most insects should be hopping, buzzing, crawling and flying around by now. The abundance of mosquitoes can be at its highest during May, due to the spring ponds, puddles and other wet areas where they lay their eggs. In Wisconsin, dragonfly nymphs change into adults two different times a year. The spring species emerge all at once in May and early June when the days grow longer and temperatures get warmer. The summer species develop at separate times throughout late June, July, and August.

When will you record your first mosquito this season? Email your spring observations to the Museum at info@cablemuseum.org and be sure to include information on the date observed, name, and the town in which you made your observations.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Thursday, May 1, 2008

Frogs & Butterflies

Nature WatchMay 1, 2008

By Susan Benson,
CNHM Director of Education

Although snow seems to want to stay, there are still many signs that tell us winter is coming to an end. Really! The loud, peeping chorus of spring peepers was heard last week. These frogs are among the very first to call and breed in the spring, often beginning when there is still ice on our lakes and snow on the ground. These frogs are found in temporary (vernal) spring ponds, or permanent ponds, marshes and ditches; following the breeding season they move into woodlands or fields. Peepers are easier to identify because they call out their name – peep, peep, peep. Sometimes peepers call while sitting under grass clumps or in crevices in the earth, allowing them to amplify their call; this technique also makes it difficult to track exactly from where the sound is coming. Other frogs to keep your ears out for include the western chorus frog that sounds like a person’s thumb pulling down a comb; the wood frog is said to sound a little like a squeaky duck quacking.

Last week’s warmth brought out a lot of butterflies. One of the most common during the warm spring days is the mourning cloak, black with yellow on the edges. These insects hibernate as adults, secreting natural antifreezes such as sorbitol into their bodies as the weather cools. They then find shelter under loose bark, in debris, or in a crevice under a roof overhang. Now, in the spring, mourning cloaks are the first to come out as their dark colors experience solar heating. Their spring food includes mostly tree sap, especially that of oaks. They walk down the trunk to the sap and feed head downward. Males will bask in the spring sun awaiting receptive females. Eggs are laid in groups circling twigs of the host plant. Caterpillars live in a communal web and feed together on young leaves, then pupate and emerge as adults in June or July. Due to their hibernation, the mourning cloak has a greatly extended adult span. While a period of about two weeks is a typical life span for most adult butterflies, mourning cloak adults live for up to eleven months. Other butterflies to keep an eye out for include the Milbert’s tortoise shell, red admirals, and the small blue spring azure.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.

Thursday, April 24, 2008

Phoebes & Juncos

Nature Watch
April 24, 2008

By Susan Benson,
CNHM Director of Education

Hellos and Goodbyes
I said “hello” this week to one of my best friends, and welcomed her back to my home in the woods. Her name is Phoebe. Some might know her as the Greek goddess of the moon, or the interesting character from the sitcom Friends. She arrived this past Wednesday, April 16, and will spend her next few months visiting me and talking with me every day. Technically, her name is Eastern phoebe. Any birder knows who I am talking of, the bold bird friend that can be observed from the arctic circle to the equator. Phoebe is one of the New World flycatchers and is a very aggressive insectivore, better known to me as the bird with a tremendous personality.

Phoebe’s color is a gray-brown, and she is a sparrow-like flycatcher with a light breast and a black bill. Every morning she greets me with her two syllable “fee-bee,” “fee-bee.” The first “fee-bee” goes down in pitch, and the second goes up. While some people might nod their heads at me in greeting, Phoebe has the habit of greeting me while bobbing her tail downward and upward again. She has a few places in my yard that seem to be her favorite perches every year, and she never appears to mind my human presence. This is one species that seems to thrive among any kind of development.

We share the same house. Every year Phoebe finds a sheltered spot under the eaves of my house to make her nest, although some birds will consider a porch or even inside a barn. 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. She doesn’t like it when I get near her nest, but each year I check in on her young to make sure they’re doing well. Phoebes are common cowbird hosts, and to combat this parasitic bird species, phoebes sometimes will build a new nest floor over top of cowbird eggs.

The eastern phoebe is the first flycatcher to arrive up north in the spring. Why does the phoebe come back so early and how does it survive when there are no insects to eat? The first field guide I looked at says that phoebes also eat berries and seeds, mostly in winter; insects and the occasional small fish or frog during other times. Phoebes also don’t go very far south for the winter, flying only to the southern United States. All other flycatchers winter in Central or South America and do not show up here until May when insects are available here.

At the same time I am greeting the phoebes around my house, I am also saying goodbye to the slate-colored juncos. Sunday morning I went for a short walk and was serenaded by the flash and song of what seemed like 40 or more juncos. This bird is a delightful uniform pale gray bird with its upperparts sharply defined against its white belly, aptly described as "leaden skies above, snow below." During the fall these small birds will fly south to inhabit much of the United States and northern Mexico in their winter flocks. During winter they will become frequent visitors to the yards of homes where food has been put out, preferring to scratch the ground for an easier meal.

Spring migration begins in around April 7th-12th as juncos fly over much of the eastern and Midwestern states on their journey north to Alaska and Canada. These birds will build up fat reserves before migrating in the spring, and will move northward rapidly in flocks of up to 100 birds. They will sometimes be accompanied by other sparrows. Male juncos will usually arrive early to establish territory for their nests. I say goodbye to these birds now, knowing they will soon find themselves the summer companion of the canoeist in the Canadian forests.

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 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.