If Andy Sigler tends to target specific birds and is willing to chase them, Walter Marcisz focuses on one area, a place of great biological richness that he knows better than anyone else. The area where Walter birds, and where he has spent all of his life, is the Calumet region, sprawling across Chicago’s southeast side into northwest Indiana. The region originally boasted 5 lakes, over 15,000 acres of marsh, and a plain with hundreds of swales and low ridges. Old accounts tell of Lake Calumet so covered with waterfowl that when the hunters began firing the flocks would rise from the water and block the sun. It also was the home of one of the continent’s great biological mysteries: Thismia Americana, a species of plant known only from one local marsh and found from about 1911-1916. It has never been seen since.
Today, two of the lakes have been mostly or entirely obliterated by fill, the sandy plain has vanished beneath cities, and most of the marshland is buried under landfills and abandoned factories. But despite the loss of habitat, the area still attracts an amazing array of birds. (Walter’s knowledge of the place and its avifauna has contributed greatly to recent conservation efforts to protect what remains.) Walter’s principal goal for our outing on June 18 was to conduct a breeding bird survey at Powderhorn Lake, a Cook County Forest Preserve that holds a fine example of sand prairie. We then visited a number of other locations that produced some wonderful sightings.
The Calumet area contains the largest population of nesting black-crowned night-herons in all of Illinois. Walter has been keeping careful track of these birds for many years. In the 1990s his counts reached totals in the “hundreds upon hundreds.” This year he tabulated about 280 birds, slightly up from 2008. But the big news is that this year there are two colonies, one of 200 and the other of 80. We visited the smaller group and could see the adults standing near their nests in the reeds. Occasionally a bird would wing over our heads and plunk down into the shelter of the marsh. Unlike some colonies in other areas, the Calumet birds nest in cattails and phragmities. This means that if water levels are low they are highly vulnerable to predators: the drought of 2005 resulted in few surviving young.
There are also two osprey nests in the area, one of which Walter just discovered this spring by accident. He was watching an osprey through his scope and was stunned to see it alight on top a cell tower. We observed the two adults, as one seemed to scold the other. Periodically, the two babies would raise their heads above the concavity of the nest.
Our last stop was Wolf Lake, which straddles the Illinois/Indiana state line. The lake is littered with mute swans, a pestiferous alien that ought to be treated like purple loosestrife (except I don’t think beetles like them). An adult male common goldeneye had been lingering on the lake, but we couldn’t see him initially. From a different angle, however, Walter spotted him bobbing on the water. Then off to lunch at my favorite Chinese buffet that features a thing almost as rare as the Calumet birds- decent sushi for little money.
Black-crowned night-heron photographed in one of the Calumet nesting colonies by Walter Marcisz.
