Wednesday, September 29, 2010

Chipmunks

Nature Watch
By Susan Thurn,
Cable Natural History Museum
Walking down the sidewalk, I heard a rustle in the undergrowth of the flower garden. I smiled when out zipped one of the chipmunk family living in the yard. Its puffy cheeks looked almost as big as its body as it crossed my path and scurried down into its tiny hole. These lively critters pudgy cheeks, stripes, and bushy tails have made them famous even in Hollywood, and for good reason.
Chipmunks eat a variety of foods including seeds, nuts, fruit, berries, fungi, insects, worms, bird eggs and nestlings, small frogs and sometimes even small mice. They gather food in areas where they can hide from their predators, and then store their food into their cheek pouches to carry to their burrow. This mammal’s scientific genus name is appropriate - Tamias, which in Greek means "storer," a behavior that this animal does so well as they collect and store food for a “long winter’s night.” Chipmunks can climb trees to harvest acorns or hazelnuts, but prefer foraging on the ground. They often spend sunrise to sunset searching for and storing food, harvesting as much as a bushel of nuts in just a few days. In August, chipmunks begin stockpiling these tasty treats in their burrows in preparation of winter. Chipmunks hibernate, but instead of storing fat like bears, they occasionally feed on their cache of nuts and seeds.

Chipmunks dig burrows with entrance holes about two inches in diameter and more than thirty feet in length. The main entrance can be found near stump or rocks, well-concealed from predators. Additional secondary entrances can exist in open areas, all part of an interconnecting underground system. The passages are two or three feet below ground. Their sleeping quarters are filled with shredded leaves and kept extremely clean. Food storage areas are in the lower tunnels to keep “refrigerated,” and leftover food shells and feces are stored in refuse tunnels. Now that is a well-planned home!
Chipmunks are important in a forest ecosystem. Their harvesting and caching activities help re-seed plants. They distribute spores of different fungi as well. They also can bring enjoyment into our lives. I know many Museum friends who enjoy chipmunks at their feeders, watch them run over their toes, and even name the often friendly creatures. Please share your own chipmunk stories at the Museum’s 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 new 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, September 22, 2010

Mushrooms

Nature Watch
By Susan Thurn,
Cable Natural History Museum

Our recent rain has been a mushroom lover’s delight. With so little rain the past few years, mushrooms seemed almost scarce in comparison. Now, when we walk through the woods we are greeted with a rainbow of colors, shapes, and sizes of amazing mushrooms. Of course they are of interest for their delectable tastes, and receive attention because of their additional ability to make those that eat the wrong mushroom extremely ill! Maybe we are more accustomed to noticing them when they are on our plate, or growing in our refrigerators. Still, they are worth our attention as we explore outdoors.

Mushrooms belong to the fungi kingdom. They cannot photosynthesize so must feed mostly on organic material. Their amazing success in reproduction is through spores, which is one reason we can find them almost anywhere. They are made up of microscopic root-like threads called hyphae. Their cell walls are made of chitin, the same material making up the shell of a crab, lobster, or dragonfly. Unlike humans who ingest their food and then digest it, a fungus digests its food first with the use of exoenzymes and then digests it with their hyphae. Because they do not need light for photosynthesis, they can live in any dark habitat, and grow in any direction. Their fruiting body used for reproduction is what we call mushrooms. Some scientists believe that molecular evidence leads to fungus being more closely related to animals then plants!

Because fungi feed on organic material, they are important in recycling nitrogen, carbon, and other nutrients. Some fungi are parasitic, feeding off of living materials and harming them in some way. Others live in beneficial relationships. Mycorrizae assist their host plants by helping the plant to capture water and elements from the soil such as zinc, phosphorus, and manganese, transferring them into the plant's roots. This fungi also protects trees against attack from pathogens. In return, the fungal partner receives from its host plant the vitamins, carbohydrates, and amino acids essential for its growth.

Fungi are much more than just the mold growing on our foods. They can break down almost every manufactured good except for some pesticides and plastics. They have been found to play a role in protecting plants in soils with high metal concentrations. They make fabulous bread and many other food products, including cheese. They are critical in antibiotics, steroids, and hormones. They even are the citric acid in our Cola! Finally, there are 250 species that are sought after food from the forest, while at the same time around the same number can be deadly or make you wish you were dead if you eat them. Mushrooms are certainly a part of our natural world that are “fun-guys” to have around.

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 new 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.

Tuesday, September 14, 2010

Fall Phenology

By Susan Thurn,
CNHM Director of Education

What good is phenology? For some, it’s a year-round hobby that helps keep them in touch with the ebb and flow of the natural world. But the practice of noting and recording seasonal changes in nature does have what some would call more practical values.

For example, phenology is used to help with the prediction of insect emergence and strategies for insect control. Farmers, of course, are phenologists, and carefully correlate natural patterns and seasonal changes with crop planting and harvesting. Scientists who study global climate change trends pay close attention to the history of phenological data.

This time of year, the most obvious seasonal change is literally right in front of our eyes, as we are nearing the peak of leaf color change among our deciduous trees. The appearance of the beautiful yellows, reds, oranges we see is actually a result of the fading of the leaf’s green color, which is caused by cholorophyll. When chlorophyll fades, “beneath” it are other types of pigments that become revealed. These are the carotenoids, which produce yellow, orange, and brown colors; and the anthocyanins, which produce red, purple, and crimson colors.

The vibrancy of fall color is related to weather conditions that occur before and during the time when chlorophyll in the leaves is dwindling. A series of warm, sunny days and cool, crisp, but not freezing nights seems to bring about the most spectacular color displays.

The timing of the color change also varies by species. For example, oaks show their colors long after other species have already dropped their leaves. The differences in timing among species seems to be genetic, for a particular species at the same latitude will show the same coloration in high elevations at about the same time as it does in warmer lowlands.

Unique among the color-changing trees is the tamarack, also known as the eastern larch. In the spring and summer the tamarack has bright green flat, soft, and flexible needles. They are shaped uniquely on the branch in a whirled cluster somewhat like a flower’s petals. The trees are easy to identify by their narrow pyramid shape and their location—they’re most common in swamp and bog areas. This tree is both coniferous (produces cones) and deciduous (loses its leaves). Although the tamarack looks like an evergreen, it is not ever-green, because its needles change to a golden-yellow color in the fall and drop off.

About this time, northern flying squirrels begin visiting oak trees to feed on acorns. As the acorns mature you might find partly chewed ones on the ground. The squirrels feed at night, so if you want to see them, look for the acorns then keep your eyes open for squirrels scrambling up the trees.

Become a phenologist! Take a fall hike and note all the different colors of the forest. Gather wild apples and make your own applesauce or cider. Soak up the fleeting warmth of sunny fall days as we turn our thoughts to colder weather.

For over 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 new 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.

Tuesday, September 7, 2010

Moths

An email from a Museum friend recently stated, “I was talking with a neighbor/friend of mine tonight about this weird bird/bug I saw in my hanging flower baskets last night. Further research proved it to be a white-lined sphinx moth! It looked so much like a hummingbird, but yet not...I just had to find out what it was.” Late summer often brings this sphinx moth around our flowers, and it can often be mistaken for a hummingbird. Another species that has similar characteristics is the hummingbird moth. Both are beautiful insects to be enjoyed this time of year as they flutter furiously about our flower gardens.

The white-lined sphinx moth has white streaks along its upper forewing and body, from which it gets its name. Adults fly mostly at dusk and dawn, but also sometimes during the day. Their wingspan can be as much as five inches, and with their rapidly beating wings, on a quick glance can be confused with hummingbirds. They feed on a large variety of flower nectar including fuchsia, bouncing bet, evening primrose, petunias and thistles.

The second hummingbird mimic is the hummingbird moth. It is much smaller than the white-lined sphinx moth, with an olive to yellow body coloring, red bands across the abdomen, and mostly clear wings. Their body really seems to mimic similar coloring as the hummingbird. These moths fly during the day, hovering at flowers as they sip nectar. Adults prefer a wide variety of flower nectar including bee balm, phlox, vetch, and thistles.

Both of these “hummingbird moths” are to be thanked for their contributions as pollinators. The caterpillars of both species are also very interesting to find and observe. It is worth some time waiting and watching for these two moth species as they travel into your own back yards.

For over 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 new 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.

Monday, August 30, 2010

Red-Tailed Hawks

By Susan Thurn,
CNHM Director of Education

This was the week of the red-tailed hawk for me, as not only did I see them in flight, but I actually held one in my hands. The bird I held was a bird that can no longer live in the wild due to a dislocated shoulder. Just seeing this bird inspired awe inside of me. We often see red-tailed hawks soaring above open fields, circling while looking for their prey. Other times we may see them perched on a telephone pole. I would also guess that we all have heard the call of a red-tailed hawk, as Hollywood seems to have chosen the red-tailed hawk as the call on almost every movie!

Holding this red-tailed hawk in my arms was most amazing. The glove that protected my arm and provided the perch for the hawk just highlighted the amazing yellow coloring of their feet. Although it is one of the largest hawks in the United States, about 22 inches high and with a wingspan up to 52 inches, it only weighs about three pounds. The colors included a darker brown back, with paler brown below, a streaked chest, and a dark bar between its shoulder and wrist as seen from underneath. The red tail for which it is named is brick-red above and pinker below.

Red-tailed hawks will eat a variety of mammals that includes mice, voles, shrews, rabbits, snakes, and squirrels. They are capable of eating prey up to five pounds in weight. Red-tailed hawks have been observed hunting as pairs, each taking a side of a tree while trying to catch squirrels.

Very territorial, red-tailed hawks will aggressively pursue other hawks, eagles, or great-horned owls. Other behavior includes an elaborate courtship ritual in which the pair locks their talons together while in flight, spiraling down toward the ground before letting go. Their flight is a soaring, shallow v-shape called a dihedral, with very little wing flapping as they conserve energy. They occasionally hover above the ground while steadily beating their wings.

I was most impressed with the red-tailed hawk eyesight as this bird watched me like a hawk, responding to my every movement. Indeed their eyesight is thought to be 8 times better than that of a human. A red-tailed hawk can see a tiny mouse while flying 100 feet in the air! That is impressive, and makes it worth exploring red-tailed hawks from our own back yards.

For over 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 new 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.

Monday, August 23, 2010

No-See-Ums

By Susan Thurn,
CNHM Director of Education

“Ouch!” I exclaim. I look down to my arm ready to swat the mosquito I am sure just bit me. Yet nothing is there. Moments later, the itch begins, and the welt soon after is at least penny sized. These are the no-see-ums, a tiny biting fly that I hate to love. Aptly named, no-see-ums are less than ¼ inch long, a little black dots the size of a period that is very difficult to see. Boy, do we feel them though!
No-see-ums often stay in shrubs or the dead leaf litter across the ground. Just walking along can stir them up. They stay close to home, though, usually not flying more than about 350 feet from their breeding area. These flies, or midges, are just like many of the other flies or mosquitoes. They are active mostly at dawn and dusk. Only the females bite us. They need the protein in our blood to make their eggs. Yet how does such a small creature do this much “damage”? No-see-ums and other flies puncture the skin with mouthparts that look like scissor blades. Their tube-like mouth is called a proboscis, and is made up of several different parts. At the end of this mouth they have receptors to sense where to begin feeding. A pair of mandibles (the scissors) cuts the skin back and forth. Another part with backward facing teeth helps to move their mouth into their prey’s body. They then inject an anticoagulant saliva into our bodies, and finally begin to draw in blood from a blood vessel. These tiny creatures feed on mammals, birds, or reptiles. Males feed on nectar.

The no-see-um larvae hatch from eggs in water, mud, or moist leaf litter. The larvae eat dead plant or animal matter. During this part of their life cycle the larvae have a spiny “tail” that entomologists use to identify them. As adults, they have two wings with dense hairs that have special pigmentation that also allows biologists to identify them.

The reaction my body has is an allergic reaction to the proteins in no-see-um saliva. Thank goodness, for me, the itching subsides in a short time. In spite of my discomfort, these small insects do provide food to other creatures, making them just as important in the food chain. In tropical forests there is one species of biting midge that helps to pollinate chocolate, which helps in my mind to negate the irritation I sometimes have at their bites. Everything has its place, after all! For chocolate alone, perhaps it is worth loving them!

For over 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 new 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.

Monday, August 16, 2010

Where Have all the Monarchs Gone?

By Susan Thurn,
CNHM Director of Education

Where have all the monarchs gone? Several Museum members have mentioned their concern that they have not been observing monarchs much this summer. Even my own searches have yielded only three caterpillars this entire season. I’ve seen only four or five adults. It is a dismal showing for one of my long-time favorite butterflies.

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. In the spring, they begin the migration north, lay their eggs, and it is their children that finish the migration to northern Wisconsin. This inter-generational migration is an amazing phenomenon. So why are the numbers of monarchs lower?

In 2002 and 2004, freezing weather in Mexico followed by heavy rains wiped out huge numbers of monarchs during those years, creating a decline in the population. Spring of 2009 brought hotter than normal conditions for monarchs migrating north again, which was followed by the one of the coldest summers since 1928 in much of the breeding area, and finally, poor conditions during the fall migration, resulting in a very small overwintering population This past February, severe hailstorms followed by 15 inches of rain in Mexico are thought to have destroyed as much as 50% of the already declining population.

Added to this problem is the ongoing issue of habitat destruction in the world of monarchs. With an increased use of genetically engineered crops to become herbicide resistant, it has become easier for farmers to spray weed killer, killing any weeds and surviving milkweed while not hurting the crops. Monarchs are also under threat in Mexico due to illegal logging at their overwintering sites.

Scientists believe it will take two or more years for the monarch population to bounce back. Even then, there are still these human factors nature provides that could be a danger to the future of monarchs. Conservation groups are encouraging us all to improve monarch habitats by planting milkweed in our gardens at home, and to encourage schools, farmers, or others with unused land to grow these beautiful perennials. Perhaps with these efforts we can continue to explore and wonder at monarchs from our own back yards.

For over 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 new 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.