Winter 2005

By Jack MacRae

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

	American tree sparrow. Photo by Jerry Kumery.

EARLY WINTER

Left Eye
American tree sparrows are one of the most commonly encountered birds during our local Christmas Bird Counts. They prefer to look for predators out of their left eye. Their flock companions, the dark-eyed junco, prefer using their right eye. Weird.

Despite their somewhat lackluster name, American tree sparrows are rarely seen in trees, and they breed in Canada, spending only the winter in the lower 48. They're cute little sparrows. Male and female look alike, with a rusty orange cap on a gray head and a dark spot in the center of their light-gray breast. Their bills are bi-colored: dark on top and yellow on the bottom. Watch for them in a field near you — they feed on the ground and have been observed eating snow.

Red and White
During fall and early winter, the photogenic partridgeberry provides nature paparazzi with a colorful subject: scarlet berries on snow. Growing low along the ground, partridgeberry's small olive-shaped leaves and bright berries on long, trailing stems create a pleasing design element in any photograph.

Partridgeberry. Photo by Barbara Money.

Partridgeberries inhabit the lovely inland flatwoods of the great sandy dunes of southern Lake Michigan in Indiana. Common in woods further north, they're rare in Illinois, but a specimen of partridgeberry was unexpectedly discovered growing along the well-drained crest of a Lake Forest, Illinois, ravine in 1977.

MIDDLE WINTER

Cold Love
During the dead of winter and under the cover of darkness, beneath the thick Lake Michigan ice, the cod are having an orgy. One voyeur/scientist described the scene as a globular, living ball of writhing fish. Eventually, clouds of freshly fertilized eggs will sink to the gravel lake floor where they'll lie, unattended, to incubate in the frigid, 4°C water.

The only freshwater North American member of the cod family is the burbot. Circumpolar in distribution, burbot used to be abundant in Lake Michigan, until they were decimated by the eel invasion of last century. Burbot look odd. They have long, cylindrical, mucus-coated bodies that attain 30 inches in length, with a single barbell that hangs from their bottom lip. They make a strange grunting sound and have the creepy ability to wrap their tail around objects in a prehensile-like fashion.

Best Western
The western harvest mouse is the smallest of the long-tailed mice. These nocturnal rodents spend the winter scampering between patches of dried vegetation, searching for seeds and avoiding the night hunters. Chicago Wilderness is at the extreme eastern edge of this creature's range. A few are found in open woodlands and grassy areas of our forest preserves. They are abundant in the great grassy plains west of the Mississippi River. Scientists can detect the presence of western harvest mice by looking for the mouse's distinctive grooved incisors among its bones in owl pellets.

LATE WINTER

	Male common goldeneye. Photo by Joe B. Milosevich.

River Deep Ducks
Not all migrating ducks seek a tropical climate for their winter holiday. Following a summer in the Canadian boreal forest, some goldeneyes will spend the winter hanging out behind a Chicago bowling alley on the north side. The great old Diversey Bowl (a unique night of fun and excitement!) is a noteworthy place to watch winter diving ducks on the adjacent Chicago River. Interestingly, it appears that on average a male adult goldeneye will spend the winter further north than adult females, who in turn will winter farther north than juveniles.

Male goldeneyes have a dark, glossy, green head with white cheek patches. Known by human hunters to be a wary bird, they avoid dangerous situations and frequent only those places where they feel secure. Besides the bowling alley, their comfort zones include the Fox River, the Chicago lakefront parks, and the Calumet area. Most common goldeneyes will depart for their Northwoods breeding grounds by the end of March.

Bitter Nuts
For those of us who smoke fish, it's been said the most flavorful and aromatic wood comes from the bitternut hickory tree. Smoked whitefish, in particular, is a real taste treat. There are some nice specimens of bitternut hickory throughout our region. They're tall and straight, without the distinctive shaggy bark of other hickory types.

One of our region's six hickory species, bitternut hickories are one of the first trees learned by students of winter botany, since their mustard-yellow terminal bud is unmistakable. Their name is fitting, too — the nuts are indeed bitter.