Birds of Prey
The nonscientific term “birds of prey” applies to several families whose members have exceptional vision for locating prey while in flight and strong talons and hooked upper beaks for handling prey once they find it. DuPage County birds of prey include hawks, falcons, harriers, eagles, ospreys, kites, vultures and owls. Their diets include small mammals, other birds, fish, reptiles, insects and carrion. Except for the owls, most are primarily active during the day.
Twice a year, many raptors migrate. They spend the spring and summer in northern areas, where they nest and rear their young. In fall and winter, when food supplies become scarce, the birds fly to more southern latitudes, where food is more abundant.
Every fall, volunteer bird monitors at the scenic overlook at Greene Valley Forest Preserve in Naperville participate in Hawkwatch, a research and monitoring program that counts migrating raptors. Data contributes to a long-term, large-scale database maintained by the Hawk Migration Association of North America, which tracks migrating raptor population numbers and trends across North America.
Hawkwatch results are summarized below. Species in bold type are listed as endangered or threatened in Illinois. Numbers listed in red represent the highest count for that species.