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.