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.

Hawkwatch Survey
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.

Accipiters

Cooper’s Hawk (Accipiter cooperii)
Northern Goshawk (Accipiter gentilis)
Sharp-Shinned Hawk (Accipiter striatus)

Accipiters are long-tailed woodland hawks with short, rounded wings, which give them greater maneuverability in the woods. They are quick in flight and often prey on smaller birds. The northern goshawk is only seen in DuPage County during migration, but Cooper’s and sharp-shinned hawks are common year-round. The latter two look similar, but the Cooper’s hawk is larger; both often prey on smaller birds at feeders.

Buteos

Broad-Winged Hawk (Buteo platypterus)
Red-Shouldered Hawk (Buteo lineatus)
Red-Tailed Hawk (Buteo jamaicensis)
Rough-Legged Hawk (Buteo lagopus)

Buteos are large hawks with broad wings and wide, rounded tails. Birders often see them circling high overhead. They feed mainly on small mammals but also prey on snakes, birds, amphibians and insects. The red-tailed hawk is the most common buteo in DuPage County. Broad-winged and red-shouldered hawks are also year-round residents but are less common. The rough-legged hawk is seen only during migration.

Eagles

Bald Eagle (Haliaeetus leucocephalus)
Golden Eagle (Aquila chrysaetos)

Eagles are about twice the size of most hawks and have proportionally larger bills and wings. The continent’s two species — the bald eagle and golden eagle — are migrants in DuPage County. Bald eagles have made a remarkable comeback from the brink of extinction, though, and have over 100 nests in Illinois. They mainly prey on fish but also eat injured ducks, carrion and small mammals. Golden eagles prey on rabbits, marmots, ground squirrels and other small mammals, insects, snakes, and birds.

Falcons

American Kestrel (Falco sparverius)
Merlin (Falco columbarius)
Peregrine Falcon (Falco peregrines)

Falcons are streamlined birds with pointed wings and medium-long tails, which allow them to reach speeds near 200 mph when power-diving onto prey. They range in size from the 9- to 12-inch-tall kestrel to the 15- to the 20-inch-tall peregrine falcon. Falcons prey mainly on birds but also hunt insects, small rodents and bats. The state-threatened peregrine falcon and merlin are considered migrants in DuPage County. The American kestrel is a year-long resident, but its numbers are declining.

Harriers

Northern Harrier (Circus cyaneus)

Harriers are slim hawks with long wings and long tails. The state-endangered northern harrier is the only DuPage County hawk in this group. They build their nests and roost on the ground. They mainly preys on mice, frogs and snakes but also eat insects, birds and dead animals.

Kites

Mississippi Kite (Ictinia mississippiensis)

Kites are graceful, falconlike birds with pointed wings. The only kite in DuPage County is the state-threatened Mississippi kite, a migrant. It feeds mainly on insects “on the wing” while flying.

Ospreys

Osprey (Pandion haliaetus)

Although smaller than bald eagles, ospreys are similar in that they primarily eat fish and live in the same habitats. These state-endangered birds with white heads and large black cheek patches currently nest in DuPage County.

Owls

Barn Owl (Tyto alba)
Barred Owl (Strix varia)
Eastern Screech Owl (Megascops asio)
Great Horned Owl (Bubo virginianus)
Long-Eared Owl (Asio otus)
Northern Saw-Whet Owl (Aegolius acadicus)
Short-Eared Owl (Asio flammeus)
Snowy Owl (Bubo scandiaca)

Owls are nocturnal. They typically live in woodlands and thickets and along wooded streams. People are most likely to hear owls at night from late winter to early spring but may see them during the day. The leading edges of their feathers are serrated, which allows for silent flight. Their ears are often asymmetrical and surrounded by feathers that they can spread to form a funnel. This funnel helps the owls to focus sound toward their ears. Because of the size and tubular shape of their eyes, owls cannot move their eyes in their sockets. To compensate, owls have deceptively long, flexible necks, which enable them to turn their heads 270 degrees horizontally and over 90 degrees vertically. 

Three owls live in DuPage County year-round: the eastern screech owl, great horned owl and barred owl. Eastern screech owls range from 7 to 10 inches tall. Great horned owls range from 17 to 25 inches tall and have two prominent tufts of feathers on their heads, which resemble horns or ears. Barred owls are also large but have more rounded faces and no feathered tufts; their undersides are whitish with dark streaks.

Five additional species sometimes appear in DuPage. State-endangered short-eared owls may seek refuge in restored forest preserve prairies and marshes, roosting on the ground or in evergreens. Long-eared owls are more uncommon; when present, they roost in dense evergreen groves near prairies and marshes. Both species may overwinter in local grasslands and marshes, often in groups. Northern saw-whet and snowy owls may also overwinter here. Northern saw-whets are quite uncommon, possibly because they are small, secretive birds that only call during the breeding season. Snowy owls are also uncommon but irruptions of sightings may occur when prey is scarce farther north. And other than individual birds that were part of a Forest Preserve District survival and dispersal program, state-endangered barn owls have not been in DuPage for quite some time.

Vultures

Turkey Vulture (Cathartes aura)

Although not necessarily impressive-looking on the ground, with a wingspan nearing 6 feet, a circling turkey vulture is a striking sight overhead. This bird of prey uses its strong sense of smell to locate food, even below a dense canopy of trees. Although it will eat some live prey, its primary diet is carrion.

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