The Cooper's Hawk is a crow-sized, very manoeuverable, forest hawk that occurs mainly in open mixed deciduous and coniferous forests. During migration it can occur in any relatively open treed area. Adults are dark gray above with a cinnamon chest and belly barred with fine lines of white. Adults also have black crowns (top of head) which are darker than the back color. That is, the dark cap contrasts with the pale nape and blue-gray dorsal area. The tail and wings are strongly barred, and the vent is pure white. The head is gray, the throat pale, and eyes red in full adults. In immatures, the eyes are gray to yellow. The beak is gray at the tip, and pale at the base with a yellow cere. The legs and feet are yellow. Colors of adult males are brighter than adult females. Immatures are brown above and vertically streaked with brown and white on the chest and belly; their wings and tails are barred, as with adults. In flight, Cooper's Hawks have short, rounded wings and a long round-tipped tail with a noticeable white terminal band. It soars and glides on level wings with wings held straight out from the body or in a slight dihedral.
It is a secretive, and often inconspicuous woodland hawk, especially during the breeding season. It breeds throughout most of southern Canada, the United States, and northern Mexico. It feeds mainly on medium-sized birds and mammals like jays and chipmunks.
The Cooper's Hawk is a common migrant at many eastern and western hawk watch locations.
SIZE
The Cooper's Hawk is strongly sexually dimorphic in size, with females being up to 50 percent larger than males. It is the medium-sized accipiter hawk, being about 50 percent larger than the Sharp-shinned Hawk but about half the size of the Northern Goshawk. Lengths average 18 inches (45 centimeters) for females and 15 inches (26 centimeters) for males. Wingspans average 33 inches (84 centimeters) for females and 29 inches (73 centimeters) for males. Weights average 19 ounces (530 grams) for females and 12 ounces (340 grams) for males. The largest females may reach weights of 1.5 pounds (675 grams).
MORPHS
There are no light or dark morphs phases for this species. Partial albinism is only known from British Columbia. A gray aberrant plumage has recently been described in California.
Specific Description
Adult - Flight
- crow-sized with short wings and long, rounded tail
- wide white terminal tail band
- head extends out from wing
- underparts barred reddish or orange
Immature - Flight
- head and neck very tawny colored
- crow-sized with short wings and long rounded tail
- wide white terminal tail band
- head extends out from wing
- underparts white and streaked with fine, neat brown lines
- breast more streaked than belly
SIMILAR SPECIES
The Cooper's Hawk is most often confused with the similar-looking Sharp-shinned Hawk. The Cooper's Hawk is much larger on average, but female (the larger sex) Sharp-shinned and male (the smaller sex) Cooper's Hawk can appear to be the same size although they never are. In flight, the Cooper's Hawk has a bulky-looking head and holds its wings straighter, whereas the Sharp-shinned Hawk has a small and narrow head and wings that jut forward at the wrist. The Cooper's Hawk usually has a rounded tail with a well-defined white terminal band, whereas the Sharp-shinned Hawk usually has a square-tipped tail with a thin white terminal band. Immature Cooper's Hawks appear light below whereas immature sharpies appear dark below. Finally, the Cooper's Hawk flaps its wings more deliberately than does the Sharp-shinned Hawk.
Immature Cooper's Hawks can also be confused at a distance with immature Northern Goshawks, which have similar plumage patterns. The immature Northern Goshwak has dark streaks on the under tail coverts while all immature Cooper's Hawks have white under tail coverts. The Cooper's Hawk underparts appear light whereas the Northern Goshawk underparts appear dirty or dark. Also, the immature Cooper's Hawk lacks the tawny bar on the wing coverts found in the immature Northern Goshawk. Northern Goshawks have deep, powerful wingbeats compared to the Cooper's Hawk more shallow and rapid wingbeat.
Small woodland buteos like the Broad-winged Hawk and Red-shouldered Hawk could be confused with the Cooper's Hawk because they occupy similar habitat and have a few similar features. However, they have broader wings and tail and fly much slower than the Cooper's Hawk.
OTHER NAMES
It has also been known as "chicken hawk", "big blue darter", and "quail hawk."
ETYMOLOGY
The scientific name Accipiter cooperii translates into "Cooper's bird of prey". William Cooper was a noted 19th century ornithologist.
