Peregrine Biology The Peregrine Falcon (Falco peregrinus) is a medium-sized raptor found almost worldwide. Three subspecies are recognized in North America, but the one you’re most likely to see in the Midwest is the American Peregrine Falcon (F. p. anatum). Its range extends from Alaska and Canada all the way south to Mexico. Historically in Illinois, Peregrines were documented nesting along the Mississippi River between the cities of Alton and Grafton, as well as near the Illinois and Wabash Rivers in Jackson County. Today, the current population follows the Lake Michigan Shoreline, with an occasional pair found in the Springfield and/or Quad Cities areas. Peregrines are naturally cliff-dwelling birds that build their nests—called eyries (EYE-reez)—on ledges. They lay their eggs in a scrape (a small depression) made in the substrate of the cliff ledge. A typical clutch size is four eggs, but occasionally a falcon may lay five. Peregrines produce only one brood per season but may try to re-nest if their first clutch of eggs fails. Unlike hawks, Peregrines don't circle the skies while scanning the ground for small mammals to snatch. Instead, these raptors are aerial hunters, known for the speed at which they can dive on other birds in flight, their primary prey. The Peregrine’s ability to take birds as large as waterfowl led to its being called the Duck Hawk. In fact, the sport of falconry—raising and training birds of prey to hunt for food—has been around for thousands of years. continue >>