Spring 2003

Natural Events

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

By Jack MacRae

EARLY SPRING

Poppy
This may not be the most relevant information to pass on to today's readers, but parts of bloodroot were once used to cure sick mules. Bloodroots bloom early in our rich woods; they often appear when patches of snow are still present in shaded areas. Open during the day and closed at night, their fragile white flower appears on a single smooth stalk. The red-orange sap, the color of dried blood, gives this beautiful little poppy its name.

Spring Beauties
Marsh marigolds are early blooming members of the buttercup family. Their showy flowers (which, instead of petals, feature bright yellow protective layers called sep-als) are set in glossy green leaves. As their name indicates, they require a wetland habitat and are found in many of our fens, forests, and flatwoods. My Wiccan friends tell me marsh marigolds are important during the ancient spring holiday of Beltane.

Hep Cats
Stone Cat and Mad Tom sound like neo-beat poets from the storied Heartland Cafe in Chicago's Rogers Park. In truth, the stonecat madtom is a little catfish (kittenfish?) that is found in a few local rivers and streams. A northern species, stonecats spawn in the spring, building their nests and guarding their eggs on the gravelly bottom. A few years back, a fishy accomplice and I found a stonecat in downtown Naperville, sharing this cobble-bottomed area of the DuPage River with several smallmouth bass and northern pike. Fish fans rejoice.

MIDDLE SPRING

Ant Eaters
Flicker meat tastes like ants, according to written accounts of sportsmen who once hunted these beautiful birds. This makes sense, as these ground-hunting woodpeckers consume more ants than perhaps any other North American bird. Although a few northern flickers stay in our urban parks and forest preserves during the winter, migrating males arrive in their breeding areas in the spring, a few days before the female. Flicker courtship is a lively affair with much head bobbing and tail fanning among several individuals.

Tiny Bubbles
According to one crazy kayaker, spring is when Bubbly Creek comes alive, as herons, coots, and migrating warblers brighten this landscape after the gray winter. Although officially known as the south fork of the south branch of the Chicago River, this little stretch of water earned its name from the large bubbles of methane gas that occasionally rise to the surface. The methane comes from untold numbers of fermenting hog and cattle wastes that were dumped into the water by the many slaughterhouses and rendering plants once found upstream. In warmer weather, the bubbling increases, resembling raindrops on the river. What a cool — albeit creepy — mix of cultural and natural history!

LATE SPRING

Back Off!
In warm and wet evenings of late May, while our fine amphibian monitors listen for the mating call of the gray treefrog, mistakes can be made. Not by the monitors, but by the frogs! On occasion, male treefrogs may grab an unwitting male from behind, prompting a distress call (I bet!) that is similar in tone, but consists of much slower pulses, than the typical anuran love song.

In our latitude, gray treefrog breeding peaks when the air temperature is 72 degrees. Secluded woodland ponds are ideal mating habitat. Though gray treefrogs are no longer as numerous as they once were in Chicago Wilderness, eastern Will County has a few large populations of treefrogs that can be heard nearly a mile away.

Locally, we have two nearly identical species of treefrogs. The only discernable difference between the eastern gray treefrog and Cope's gray treefrog can be found through examination of their chromosomes and — more important to any listening monitor — their loud mating calls. The trill rate of the Cope's is a bit faster. A calling male of either species can produce a blast with a sound pressure level of approximately 100 decibels at one foot away.

Beach Boys and Girls
Thirty years ago this May, a single piping plover nest was found on the pebble beach in Waukegan. Sad, as this was the last known local nesting of these cute little shore birds. They stopped nesting in Indiana in the 1950s. But just a century ago, local ornithologists considered these nests common in our sandy dunes and along the Lake Michigan shoreline. Despite efforts to protect potential nesting sites, piping plovers remain extremely rare, with fewer than 40 breeding pairs in the Great Lakes region, and perhaps less than 6,000 individuals in the world.

Silk Moths
The largest moths in the North American continent don't flourish best in mature forests — too many rodents. But cecropia moths do succeed in many neighborhoods where their primary predators, white-footed mice, aren't so abundant. In mid May, after safely spending the winter enclosed in their cocoons, adult cecropias emerge into the morning sun. For the rest of the day they sit quietly, drying their large, red-brown wings. Mating will occur just before the next dawn, as males search out the waiting females.