"There was a time in this fair land…When the green dark forest was too silent to be real"—from the song Canadian Railway Trilogy by Gordon Lightfoot
After the back country road that I traveled on emerged from the steep bluffs and ravines of the La Moine River valley, the land became gently rolling and then mostly flat. And the view opened up to expose miles of snow-covered agricultural fields whose crops had been harvested months before. It seemed a lonely land, bleak and lifeless. Then just about as that thought emerged, a large rough-legged hawk, flying not more than 100 feet from the road, caught my attention.
Juvenile Rough-legged Hawk (Photo by Vic Berardi, used by permission)
It was on the hunt, searching for whatever small mammals might be out foraging for food scraps like waste corn or soybeans left over from fall harvesting. I was especially excited to see this bird because while rough-legged hawks routinely overwinter in Illinois, they nest in the high arctic tundra, a land of diminutive plants, too far north for trees; an unforgiving land shared with polar bears, barren ground grizzly bears, muskox, caribou, and snowy owls. A more different world from central Illinois it would be hard to imagine, and yet I wondered if the winter landscape in view might superficially resemble the tundra.
Caribou on the tundra (photo by Kyle Joly downloaded from the National Park Service
at www.nps.gov 22 February 2021)
The rough-legged hawk is a link to that faraway land, a place I am unlikely to ever see in person, but which I know is there; the living rough-legged hawk is proof; and when I see one, I am always reminded that there were periods when tundra-like environments existed in Illinois: during the Ice Age. From about 75,000 to 10,000 years ago, the most recent glacier extended from the Arctic, for a time reaching into the Midwest and covering much of what would one day be the northeastern third of Illinois. Steppe tundra (grasses, sedges, and herbs with few trees) and forest tundra developed along the glacier’s margin, where surely there were rough-legged hawks.
How strange it is to imagine Illinois with tundra, boreal forest, and glaciers. Even stranger are some of the fauna of that time, which would have included species that went extinct after the Ice Age: mammoths on the tundra; mastodons in the nearby boreal forests; and the giant short-faced bear, larger than a polar bear, an unopposed super predator, roaming the land at will. But that environment would have seemed normal to the few humans who coexisted, having only arrived in North America for the first time near the waning years of the Ice Age, roughly 12,000 years before the present; just as what greeted the first Europeans to see the Illinois country in the seventeenth century—extensive grasslands, open woodlands, and savanna—would have seemed normal to them; as a land of vast corn and soybean farmlands seems normal to me. The word “normal,” though, requires an agreed upon point of reference. Writing for Time-Life Books in 1983, Windsor Chorlton had this to say: Human beings have never experienced the earth’s normal climate. For most of its 4.6-billion-year existence, the planet has been inhospitably hot or dry and utterly devoid of glacial ice. Only seven times have major ice eras, averaging roughly 50 million years in length, introduced relatively cooler temperatures; humankind arose during the most recent of those periods.
Muskox on steppe tundra. A diorama at the Illinois State Museum
illustrating Ice Age Henderson County, Illinois (downloaded on 22 February
2021 from iceage.museum.state.il.us)
As the climate warmed and the ice retreated back northward, so also did the tundra and boreal forest. Individual plants would have survived or died out as the changing environment allowed; but for each species, continually shifting the boundaries of distribution along with favorable conditions; so that, gradually over many years, tundra gave way to boreal forest, with both eventually no longer able to survive in Illinois. Deciduous forest and prairie species would then thrive where tundra and spruce forests could not. And this reminds me that the state of nature is continually poised for change, ready to exploit or avoid a situation when the time is appropriate. Change, in fact, in the final analysis, is the norm; not any one set of conditions that happen to be there when we start paying attention.
Oh, where the line of thought leads beginning with a simple rough-legged hawk sighting! Images of where that bird came from, what it might have seen in its life, and what other individuals of the species may have experienced through deep time. Then, seeing the land in front of me not as it is, but as it had been, and what it might become.
But soon the spring bird migration will be underway, with species returning to Illinois from the southern hemisphere. Where in time and place might sightings of those migrants take me?
Selected References
Berkson, A. and Wiant, M.D., editors. 2001. Discovering Illinois archaeology. Illinois Association for the Advancement of Archaeology and the Illinois Archaeological Survey.
Chorlton, W. 1983. Ice ages. Time-Life Books, Alexandria, Virginia.
Illinois State Museum. iceage.museum.state.il.us referenced on 22 February 2021.
Killey, M.M. 1998. Illinois’ ice age legacy. GeoScience Education Series 14. Illinois State Geological Survey, Champaign, Illinois.
Pielou, E.C. 1991. After the ice age: the return of life to North America. The University of Chicago Press, Chicago and London.