Fall 1998

[TEXT ARCHIVE WEB-PUBLISHED MARCH 2002.
ORIGINAL PRINT PUBLICATION DATE: FALL 1998.]

Here's what's debuting this season
on nature's stage in Chicago Wilderness

By Jack MacRae

Fall Into Winter

Northern Leopard Frogs
Like children gathering on the school yard for recess, large numbers of northern leopard frogs have congregated in the sedge meadows by their winter home — under water. Soon they will sink into the water for the final time this year, not emerging until the warm days of spring. Northern leopard frogs hibernate in the icy water, burrowing under submerged logs and rocks at the muddy bottom of the pond. They don't breath through their lungs underwater, but rather absorb oxygen directly through their skin. While the water is certainly cold — below 40°F — the deeper water does not freeze solid. This is good news for these amphibians who can survive being chilled to 30°F but perish before the temperature reaches 28°F.

Turtles On The Rocks
Remember those baby snapping turtles we've been following the last few issues of Chicago WILDERNESS? The youngsters are now starting their first winter when they face the appealing notion of crawling along the muddy bottom and breathing through their butts. What fun! Amazingly, many snappers remain active despite the frigid water. Large snapping turtles have been found frozen solid within a block of ice, fully conscious with eyes blinking.

Frog Popsicles
Spring peepers are one of the few animals that are able to survive prolonged exposure to sub-freezing temperatures. Rather than finding a (relatively) warm winter home on land below the frost line, or in water under the frozen ice, spring peepers spend the winter on the surface of the forest floor, covered by the leaves that accumulate on the soil. Here the air temperatures often reach below zero and the bodies of the spring peepers actually freeze, with ice crystals forming inside them. Due to a natural anti-freeze made of glucose however, the vital fluids within their cells don't freeze and peepers survive the Chicago Wilderness winter.

Samantha's Cousin?
Witch hazel may sound like a character on "Bewitched," but it is really an attractive tree native to the understory of our wooded areas. Blooming at this time of year, later than most flowering shrubs of the Chicago Wilderness, this short tree produces slender, bright yellow blossoms. These faintly fragrant flowers are interesting in that they are produced only after the tree's toothed leaves have turned from green to yellow and fallen to the ground. Another distinctive quality of the witch hazel is that its fruit takes a full year to ripen. Its small brown pods violently eject last year's shiny, black seeds 20 to 30 feet away.

Named by early American settlers because it resembled the hazel tree native to Europe, the witch hazel does not refer to witchcraft or sorcery but probably comes from the old English word meaning "to bend." The branches of the Witch hazel were made into divining rods, used for water witching, an archaic term for the practice of locating water and minerals below the ground by means of bending sticks.

Snake Hibernacula
Hibernaculum is an obscure word indicating the location where an animal hibernates. This is the time of the year when our local reptiles are seeking a hibernaculum in which to sleep through the cold weather. Historically, hibernacula were often located in cracks and fissures of rocky bluffs and ravines. In Chicago Wilderness, I have seen an old, cracked railroad trestle used by many garter and fox snakes for their winter home. With so many of our natural geographic features destroyed, we are fortunate that artificial structures have value as a winter home to our cold-blooded friends.

Stone Flies
I'm a big fan of hot, humid summer weather but can appreciate the cold temperatures for two reasons. First, beer stays cold on my back porch. Second, there are fewer biting bugs. Amazingly, not all insects disappear during the cold months of late autumn and early winter. The common stone fly is actually quite active at this time of year. Living in small streams, the larval stage of the stone fly is feeding on water plants and growing larger. An important part of a freshwater fish's diet, these nymphs are intolerant of polluted or poorly oxygenated water and thus are indications of good water quality. Thousands of these creatures have benefited from people working to restore and stabilize the banks of the many streams that criss-cross the Chicago Wilderness.

White Owls
When I run out of a food staple, say chips and salsa, I go to the local grocer or convenience store. When snowy owls start to run out of food, they head south. Due to periodic fluctuations of the rodent populations, these large white predators occasionally expand their territory in search of food. Usually inhabiting the open plains of the treeless tundra, snowy owls are often spotted in the Chicago Wilderness during these southern wanderings. On gray winter days they can sometimes be seen sitting atop sand dunes and breakwaters along the Lake Michigan shore line.

One December day, several years ago during the Education Staff Christmas Party at the Field Museum, a snowy owl was spotted sitting on the roof, outside a third floor storage room. The following year, during the same holiday function, a group of us ventured back to the same storage closet and peeked out the window. Sure enough, this beautiful bird of prey was there again, this time sitting only a few feet from the window, looking at us with his vivid yellow eyes. Some things you never forget.

Christmas Bird Count
This is the 99th year of a truly wonderful event that occurs during our holiday season. Every year since 1900, groups of bird watchers have fanned out across the continent to inventory the local avian fauna. Started in 1900 by Frank Chapman, long-time Curator of Ornithology at the American Museum of Natural History, the Christmas Bird Count was organized as a protest against the longstanding holiday tradition in which organized teams would compete to see who could slaughter the most birds in one day. Unbelievable.

The Chicago area has multiple opportunities for participating in this year's Christmas Bird Count, with programs occurring from mid-December through early January. Some of the sites for the count include Indiana Dunes, urban Chicago, FermiLab, and Waukegan. The best place to learn additional sites and details about this valuable event is by contacting the Chicago Audubon Society at (773) 539-6793.