Jacksonville Zoo and Gardens

Cooper's Hawk

Accipitridae

Falconiformes

Aves

Belize, Canada, Colombia, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, and United States; Vagrant: Bermuda

Various types of mixed deciduous forests and open woodlands, including small woodlots, riparian woodlands in dry country, open and pinyon woodlands, and forested mountainous regions

Adult male length and weight: 14-18 in (35 - 46 cm), 7.7-14.5 oz (220 - 410 g); adult female length and weight: 17-20 in (42 to 50 cm), 11.7-24 oz (330 - 680 g); wingspan: 25-36 in (62 to 90 cm); appearance: short rounded wings and a very long tail with dark bands, round-ended at the tip; coloration: eyes are red with a black cap, blue-gray upper parts and white underparts with fine, thin, reddish bars; tail is blue gray on top and pale underneath, barred with black bands; immatures have yellow eyes with a brown cap, brown upper parts and pale underparts with thin black streaks mostly ending at the belly; tail is brown on top and pale underneath, barred with dark bands.

Average in the wild: 12 years; the oldest known Cooper’s hawk was 20 years, 4 months old.

Approximately 2 years

In the wild, they eat a variety of prey – robins, jays, starlings, quail, songbirds, woodpeckers, doves, small mammals, and possibly snakes, lizards, frogs and large insects; in the Zoo, they are fed a scientifically developed, commercially available bird of prey food and a variety of prey items: chicks, mice, and small rats.

IUCN – Least Concern; CITES – Appendix II & III (Puerto Rico); US – Migratory Bird Treaty Act

Cooper’s hawks are diurnal. They spend much of their time perched and waiting to ambush passing birds. They migrate yearly between their summer breeding grounds and their southern winter range. They are mainly a solitary species that come together only to breed.

The Cooper’s hawk appears long-necked in flight and has been described by birdwatchers as looking like a “flying cross”. It is seen mostly flying with quick, consecutive wing beats and a short glide, though they may also soar. An attack maneuver is to fly fast and low to the ground, then up and over an obstruction to surprise prey on the other side.

These birds capture prey from cover or while flying quickly through dense vegetation, relying almost totally on surprise. One study showed that this is a quite dangerous hunting style. More than 300 Cooper’s hawk skeletons were investigated and 23% revealed healed fractures in the bones of the chest. Birds preyed on can range in size from wood-warblers to ring-necked pheasants. They may also prey upon another raptor, the American kestrel. They rob nests and also eat small mammals like chipmunks, hares, mice, squirrels, and bats. Other possibilities are lizards, frogs, snakes and large insects. It normally catches its prey with its feet and kills it by repeatedly squeezing it and holding it away from its body until it dies. They have also been seen drowning their prey, holding it underwater until it stops moving. In addition, they often pluck the feathers off their prey on a post or other perch. They are increasingly seen hunting smaller songbirds in backyards with feeders. They will perch in trees overlooking the feeders, then swoop down and scatter the other birds in order to capture one in flight. These hawks can also pursue their prey on the ground by half running and half flying.

Cooper’s hawks are monogamous and most mate for life. Pairs will breed once a year and raise one brood per breeding season. Courtship displays include stylized flights with the wings positioned in a deep arc. During their flight displays the male will begin by diving toward the female. A slow speed-chase follows involving the male flying around the female exposing his expanded under tail coverts to her. The male raises his wings high above the back and flies in a wide arc with slow, rhythmic flapping. Courting usually occurs on bright, sunny days, in midmorning. After pairing has occurred, the males make a bowing display before beginning to build the nest.

Their breeding habitats are forested areas. A pair builds a stick nest with a cup depression in the middle in a large tree over a two week period. Nests are typically 25–50 feet above the ground and out on a horizontal branch. Usually 3 to 5 cobalt blue eggs are laid. The female incubates the eggs 30 to 36 days. The hatchlings are completely covered in white down and are brooded for about two weeks by the female, while her mate forages for food. The fledging stage is reached at 25 to 34 days of age, though the offspring will return to the nest to be fed until they become independent around 8 weeks. Eggs and nestlings are preyed on, rarely, by raccoons, crows as well as other competing Cooper’s hawks. Adults rarely fall prey to red-tailed hawks, great horned owls and Northern goshawks.

Cooper’s hawks communicate using vocalizations and displays. Vocal is probably preferred over display, because the denseness of their habitat could prevent displays from being seen from a distance. Males are usually submissive to females and will listen for reassuring call notes the females make when they are willing to be approached. Males have a higher pitched voice than females.

Little is known about the degree of territoriality among Cooper’s hawks. However, they do appear to maintain a minimum distance between nests of 0.43 – 0.62 miles (0.7 to 1.0 km).

The eyes face forward, enabling good depth perception for hunting and catching prey while flying at top speeds. The hooked beak is well adapted for tearing the flesh of prey.

The Cooper’s hawk was first described by French naturalist Charles Lucien Bonaparte in 1828. It is a member of the goshawk genus Accipiter. This bird was named after the naturalist William Cooper, one of the founders of the New York Lyceum of Natural History (later the New York Academy of Sciences). Other common names include: Big Blue Darter, Chicken Hawk, Hen Hawk, Mexican Hawk, Quail Hawk, Striker and Swift Hawk.

Individuals living in the eastern part of the range tend to be larger and heavier than those in the western part of the range.

Cooper’s hawks impact the populations of the animals they prey on. They are also hosts for several species of parasites, including larval dipterans, mallophagial lice, tapeworms and helminthes.

Once thought averse to towns and cities, Cooper’s hawks are now fairly common urban and suburban birds. Some studies show their numbers are actually higher in towns than in their natural habitat, forests. Cities provide plenty of rock pigeon and mourning dove prey. One study in Arizona found a downside to the high-dove diet: Cooper’s hawk nestlings suffered from a parasitic disease they acquired from eating dove meat.

Cooper’s hawk populations declined as a result of the use of pesticides such as DDT, but have begun to recover since DDT was banned in 1972. One threat facing Cooper’s hawks today is degradation and loss of habitat. Management activities such as logging may make former habitat unsuitable for breeding.

Cooper’s hawks are protected under the United States Migratory Bird Act and by CITES Appendix II which regulates the international trade of this species. They are listed under CITES Appendix III in Costa Rica.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion. The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion. The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion. For these reasons the species is evaluated as Least Concern.

Part of our inventory from 1998 to 2000, this hawk was once again added to the animal collection in 2004.

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