DEEP: Cooper's Hawk Fact Sheet

Cooper's Hawk Fact Sheet

Accipiter cooperii

Copyright 1997
Habitat: Deciduous woodlands; occasionally coniferous forests.
Weight: Males-13.5 ounces; females-1 pound, 4 ounces.
Length: 14-21 inches.
Wingspan: 27-36 inches.
Life Expectancy: One banding record indicates over 7 years.
Food: Birds, ranging in size from nestling songbirds to crows and woodpeckers; small mammals; occasionally fish, red squirrels and chipmunks.
Status: State threatened.

Identification: The Cooper's hawk is longer and leaner than the similar-looking sharp-shinned hawk. Adults have blue-gray backs and rusty barring on their underparts. A blackish crown contrasts strongly with the back. Immature Cooper's hawks have whitish or buffy underparts with fine dark streaking restricted to the chest. The rounded tail appears disproportionately long. It is crossed with four or more obscure black bars and has a broad, distinctly white tip. The sexes are similar in appearance, but the female is larger in size. Like all accipiters (a genus of small hawks with short wings and long tails), the Cooper's hawk flies with several quick wing beats and a glide.

Range: The Cooper's hawk is found throughout much of the United States. Its range extends from southern Canada to Florida and Texas. The species winters south through Mexico to Guatemala and Honduras.

Reproduction: The male Cooper's hawk selects the nest site, which is usually in a hardwood or pine tree. The nest is a platform of sticks or twigs lined with bark that is built 10 to 60 feet above the ground. Occasionally an old crow's nest is used. The 4 to 5 bluish white eggs are spotted with brown. The female incubates the eggs for 32 to 36 days. During incubation and the early nesting stage, the male does most of the hunting. Young Cooper's hawks are able to fly when they are about 24 days old, but they are dependent on the adults for food for 30 to 40 more days.

Reason for Decline: Historically, this hawk was referred to as the "chicken hawk" because it preyed on chickens brought over by the colonists. Consequently, the species, and many others that resembled it, such as the sharp-shinned hawk and goshawk, were persecuted by farmers and almost exterminated. Even into the early 1900s, a negative attitude persisted toward these hawks. In the early 1970s, a serious decline in the population of Cooper's hawks was reported. This decline was the result of pesticides, namely DDT, which caused eggshell thinning.

History in Connecticut: In the 1800s, the population of Cooper's hawks began to decline as farmers eliminated large numbers of them, but the species was still considered a common nester in the early 1900s. By the 1930s, it was reported that the population had decreased to one-third of its former numbers. Pesticide contamination in the 1970s caused a further reduction in numbers. The Cooper's hawk is listed as a threatened species in Connecticut due to its small breeding population in the state.

Interesting Facts: Cooper's hawks tend to be solitary birds. They are not inclined to travel in pairs or small groups, and they are generally much less common than sharp-shinned hawks during migration.

After catching a bird or small mammal in its talons, the Cooper's hawk will sometimes fly to water to drown its prey.

"Big blue darter" is a common name once given to the Cooper's hawk that reflects both the bird's blue-gray coloration and swift, agile flight in wooded areas.

Protective Legislation: Federal - Migratory Bird Treaty Act of 1918. State - Connecticut General Statutes Sec. 26-311.

What You Can Do: The conservation of woodland raptor populations is dependent on forest management practices. More knowledge is needed to determine what effect forest maturation and composition has on this species.

Cooper's hawks may occasionally be seen preying on songbirds near winter bird feeders. Although this can be a traumatic experience for some feeder watchers, it is important to remember that these hawks are part of the food chain and must prey on other birds to survive. Hawks breed less often than smaller songbirds and produce fewer young.

Since woodland nesting species such as the Cooper's hawk are often difficult to survey and monitor, any confirmed nests should be reported to the Wildlife Division to help increase our knowledge of the activities of these birds in Connecticut.

Connecticut Range

{Connecticut Range Map}

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The production of this Endangered and Threatened Species Fact Sheet Series is made possible by donations to the Endangered Species-Wildlife Income Tax Checkoff Fund.
(rev. 12/99)