The peregrine falcon is also known as the duck hawk. It averages 15 to 20 inches in length (tail tip to bill tip in preserved specimen). Like all falcons, it has pointed wings, a thin tail and a quick, ﬂapping motion in ﬂight. The peregrine’s dark “sideburns” are distinctive. The adult has a blue-gray back, while the chest and belly are white to orange with darker spots and bars. The immature falcon has the same head and facial patterns as the adult but is brown on the upper side. The lower side of the immature bird is cream-colored with brown streaks.
The peregrine falcon is a migrant, winter resident and summer resident in Illinois. It was extirpated from the state, reintroduced and populations have recovered. The peregrine falcon lives in open areas, like prairies, along Lake Michigan and around other rivers and lakes, especially if large flocks of shorebirds and waterfowl are present. It has also been introduced to cities. Spring migrants begin arriving in March. These birds previously nested in Illinois on cliffs and in hollow trees but now may nest on ledges or roofs of tall buildings or bridge structures in urban areas. Three or four, white eggs with dark markings are deposited by the female, and she incubates them for the entire 33- to 35-day, incubation period. Fall migrants begin arriving in Illinois in August. This bird winters as far south as the southern tip of South America. The peregrine falcon eats birds, rodents and insects. It can dive at speeds up to 200 miles per hour to catch its prey. Its call is “we-chew” or “kek, kek, kek.”