Thursday, June 25, 2009

Musky-Top of the Food Chain

Nature Watch

By Susan Benson,
CNHM Director of Education

Huge amounts of time, and money, are spent in search of the famous musky. A muskellunge, Esox masquinongy, is a large, fairly uncommon freshwater fish of the north woods. The name comes from the Ojibwe word maashkinoozhe, meaning "ugly pike". The original musky range in Wisconsin was mostly confined to lakes and rivers in the drainage of the Chippewa River above Chippewa Falls, the northern part of the Wisconsin River, and the Amnicon River near Superior. The distribution has been extended to other places mostly through stocking.
At the top of the lake food chain, these ambush predators sit and wait, capturing their prey by stealth and cunning rather than strength or speed. They usually hide motionless, waiting for their prey to come within striking distance. They are well camouflaged with dark vertical stripes on their sides that tend to break up into spots. Muskies tend to prefer clear waters where they lurk along weed edges or rock outcrops to rest, acting as good spots for finding their food. They have a large mouth with many large, hair-like teeth that allows them to eat fish, snakes, frogs, mammals, ducklings, muskrats, mice, spiders, or crayfish. They will take their prey head-first in a single gulp, and will eat prey up to 30% of their own body length. When their metabolism is slower in the spring, they choose smaller bait, and before winter begin eating larger food items.
During the summer muskellunge will form two home ranges - in the shallow areas and deep areas. Known as a loner, they conceal themselves in shallow vegetation, and will stay in those ranges, searching for food depending on the water temperature and clarity of the water. Other times they will move offshore and remain sedentary in deep water. Their home range is usually less than twenty acres. When water temperatures go higher than 80 degrees Fahrenheit, their movement decreases, and optimum temperatures are in the 70’s.
Growth of musky can change even among fish within the same lake. For those who catch and release a 12-inch fish, it will generally be one year old; a 24-inch fish at three years, and a 37 to 45-inch fish could be over ten years old. Females grow faster than males so can become much larger. These growth rates are also variable depending on lake conditions. For example, musky in Wisconsin have been known to be twenty years old, and measure less than thirty inches in length. To see any musky is quite exciting, and to see one follow a lure to the boat is a highlight of anyone’s day. Enjoy the waters of the north woods during the upcoming Musky Festival!
For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Monday, June 22, 2009

Mid-June Phenology

Nature Watch

By Susan Benson,
CNHM Director of Education

Have you seen a fawn followed by its mother? How about a yellow, tiger swallowtail around the lilacs or flying through your yard, or an orange flower blooming? If you notice these sorts of things, then you're a phenologist! Phenology is the study of the behavior of animals and plants in relation to changes in climate and season. Take some time out to notice what is changing this time of year.

Bogs are a beautiful place to visit with the multitude of flowers blooming in them. Some of the flowers currently blooming are white tufts of the cotton grass, the small pink bog laurel, Labrador tea, or three leaved Solomon's seal. Pink lady slipper orchids are at the tail end of their blooming seasons. To discover an amazing, accessible bog, try the Uhrenholdt Forest in Seeley, on County Highway OO, on the north side of the road. A boardwalk goes right through the center of the bog. Bogs are truly amazing places to visit!

Other woodland flowers that are blooming in mid-June are blueberry, yellow barren strawberry, and fringed polygala. Wild strawberries ripen. The first white-tailed deer fawn can be seen in forest areas. The first fireflies are also observed, usually in mid- to late-June. These are all events to watch for in the forest.

In meadow areas, we see yellow, tall buttercups, orange or yellow hawkweed which will soon be blooming, and the ox-eye daisies which will follow after. Do hawks eat hawkweed plants to improve their vision? According to a folktale this is how this plant was named. In fact, hawkweed was brought to America by herb doctors to cure eye diseases. Hawkweed is also referred to as the "devil's paintbrush" because it invades farmers' fields. Similar hawkweeds are yellow. The ox eye daisy belongs to the composite family and is named for its multiple, tiny disk flowers in the yellow center, surrounded by the twenty to thirty white "petals" (each "petal" is actually an individual flower.) The ox eye daisy is native to Europe but has naturalized throughout all regions of the United States. In England, the name daisy means "the day's eye," because it closes at night and opens in the day. Another common name is bruisewort, because its crushed leaves were often used for soothing bruised skin. The daisy has also been used to tell fortunes. Many people have played "he loves me, he loves me not" with the daisy. Since the daisy usually has an uneven number of petals, if you start with "he loves me," chances are pretty good that you will end with "he loves me."

In becoming a phenologist, flowers are a good place to start. Wildflowers come in seasonal cycles, they are often colorful and pretty, and they are relatively easy to locate because they don't move around or run away—like birds or other wildlife. Keeping a phenology notebook is an easy way for youngsters and adults alike to begin developing naturalist skills in order to learn more about the natural world around 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 and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.

Thursday, June 11, 2009

Monarchs

Nature Watch

By Susan Benson,
CNHM Director of Education

Monarch butterflies are friendly visitors to northwest Wisconsin. In fact, there aren’t many places on this continent that Monarchs aren’t found this time of year.

This butterfly’s range covers the same ground as does the milkweed plant. That is no coincidence, as the milkweed is the Monarch’s primary source of food. This plant provides the butterflies with nutrition, but something else too. Milkweed produces poisonous chemicals called cardiac glycosides. In humans, these chemicals increase the force of contraction of the heart. Monarchs have adapted to the plant’s effects, so a meal of milkweed doesn’t affect them. However, after eating milkweed, the Monarch itself becomes poisonous—an intriguing form of chemical protection. The beautiful orange color of the Monarch butterfly warns its predators that their intended meal might be toxic.

During the summer, female Monarchs each lay about 400 eggs on the underside of leaves of milkweed plants. The eggs develop for about two weeks, slowly changing color from yellow to light gray. Eventually the caterpillar’s head becomes is visible through its eggshell. At hatching, a caterpillar’s head is larger than the rest of its body; with its jaws, the caterpillar cuts through the egg and waves its head and body to break free.

On the first day of life, the caterpillar consumes its own weight in food, and its first meal is the eggshell. Over the next few days, the caterpillar eats day and night, only stopping to rest between meals. Fully developed, the caterpillar is about two inches long and weighs 2,700 times more than when it hatched.

After two weeks, the caterpillar comes to rest and starts to form a chrysalis. This stage in the insect’s life is the most amazing. Inside the chrysalis, the caterpillar forms wings, the body changes from worm-like to insect-like, and the brilliant orange color of the wings is created.

As adults, Monarch butterflies are migratory creatures. They travel great distances each fall to spend winter in temperate climates. Despite the fact that the range of the Monarch’s summer home is quite expansive, the wintering grounds are very limited. Some of these butterflies travel more than 2,900 kilometers to spend winter in places such as Michoacan, Mexico. Other Monarchs overwinter in Cuba, and Pacific Grove, as well as Newark, California.

Saturday, May 23 was the first time I saw a monarch this season. Other common butterflies that can be observed right now include the yellow tiger swallowtail and the tiny blue butterfly called the spring blue. Keep your eyes out for these adult beauties. Or, if you see milkweed plants, try turning over a few leaves for their light green monarch eggs.

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

Thursday, June 4, 2009

Bird Senses

Nature Watch

By Susan Benson,
CNHM Director of Education

Birds have the same basic five senses we do: sight, hearing, touch, taste, and smell. However, their senses are a bit different because they are custom-tailored for a bird’s way of life. Like people, sight and hearing are the most important senses for birds.

Birds as a group have one of the most highly developed senses of vision in the animal kingdom. The importance of this sense is best illustrated by the larger size of a bird’s eyes relative to other animal groups. For example, heads of both humans and starlings represent about one-tenth of total body weight. The starling’s eye, however, represents fifteen percent of its head weight, compared to less than one percent in humans. An owl, if it could read, could read a newspaper from the other end of a football field. A golden eagle can see a rabbit on the ground from two miles away. Finally, if our vision was the same as birds of prey, our eyes would need to be the size of grapefruits. Now that is amazing eyesight!

The sense of hearing in birds is well developed. The inner ear functions in essentially the same way as a human’s. Songbirds hear in a range of frequencies narrower than those in which a human can hear. If you can’t hear a sound, chances are neither can birds.

For birds, the sense of touch is concentrated primarily in their feet and bill, the areas that are not feathered. Their feet detect feelings of cold, heat and pain. Many birds have a highly developed sense of touch in their bill, which they employ when capturing and manipulating food.

Experiments with birds indicate they have an acute sense of taste, but they have fewer taste buds than mammals. Some birds are insensitive to bitter, sweet, or sour tastes. Aren’t they lucky?

How widespread or important the sense of smell is in birds has been long debated. Research has shown that turkey vultures use smell to locate dead animals to eat. Of all senses, smell is generally the least developed in birds, although their detection and discrimination ability varies considerably among species.
Aesop said, “It is not only fine feathers that make fine birds.” This is certainly true! Next time you see a turkey vulture on its food along the roadsides, just think of the smell they get to enjoy at every meal. Or envy the birds that never have to be tempted by sugar. Whatever they do, birds continue to appeal to our sense of wonder!
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibits, the Curiosity Center and Brain Teasers 2, in Cable at 13470 County Highway M. Also find us on the web at www.cablemuseum.org to learn more about exhibits and programs.