Wednesday, November 24, 2010

Cottontail Rabbit

Nature Watch

By Susan Thurn,
Cable Natural History Museum

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

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

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

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

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

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

Thursday, November 18, 2010

Ruffed Grouse

Nature Watch

By Susan Thurn,
Cable Natural History Museum

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

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

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

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

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

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

Wednesday, November 10, 2010

Fox Sparrow

Nature Watch

By Susan Thurn,
Cable Natural History Museum

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

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

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

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

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

Wednesday, November 3, 2010

Fall Leaf Decomposition

Nature Watch

By Susan Thurn,
Cable Natural History Museum

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

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

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

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

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