These are photos that I captured yesterday on my family’s
ranch. They are of an Immature female Cooper’s Hawk. We were outside enjoying
our evening on the porch when we noticed that all of the birds in the area were
really making a racket, after a while of looking to see what was causing the
disturbance we finally spotted the Hawk perched in up in the Mesquite tree. I
am thankful that she let me get up close enough to her to get a few shots. You can also purchase prints and products featuring these photos here My Website
Cooper's
Hawk (Accipiter cooperii) is a
medium-sized hawk native to the North American continent and found from
Southern Canada to Northern Mexico. As in many birds of prey, the male is
smaller than the female. The birds found east of the Mississippi River tend to
be larger on average than the birds found to the west.
Taxonomy:
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) in New York.
Other common names; Big Blue Darter, Chicken Hawk, Hen Hawk,
Mexican Hawk, Quail Hawk, Striker and Swift Hawk
Description:
The average size of an adult male ranges from 7.8 to 14 oz
with a length between 14 and 18 in. The adult male is significantly smaller
than the average female, which weigh 12 to 25 oz and measure 17 to 20 in long.
Its wingspan ranges from 24 to 37 in. Individuals living in the eastern
regions, where the sexes average 12.3 oz and 20.0 oz, tend to be larger and
heavier than those in the western regions, where the respective sexes average 9.9
oz and 16 oz. Cooper's Hawks have short rounded wings, the wing chord measuring
8.4–10.9 in. long, and a relatively long tail, 6.7–8.1 in. long, with dark bands,
round-ended at the tip. As in most Accipiters, the tarsus is relatively long,
measuring 2.2–3.0 in long, and the bill is relatively small, with the culmen
from the cere measuring only 0.59–0.83 in.
Adults have red eyes and have a black cap, with blue-gray
upper parts and white underparts with fine, thin, reddish bars. Their tail is
blue gray on top and pale underneath, barred with black bands. Immatures have
yellow eyes and have a brown cap, with brown upper parts and pale underparts
with thin black streaks mostly ending at the belly. Their tail is brown on top
and pale underneath, barred with dark bands. The eyes of this hawk, as in most
predatory birds, face forward, enabling good depth perception for hunting and
catching prey while flying at top speeds. They have hooked bills that are well
adapted for tearing flesh of prey. Immatures are somewhat larger than a
Sharp-shinned Hawk and smaller than a Northern Goshawk, though small males
nearly overlap with large female Sharp-shinned Hawks, and large female Cooper's
Hawks nearly overlap with small male Goshawks. The Cooper's Hawk appears
long-necked in flight and has been described by birdwatchers as looking like a
"flying cross". The Cooper’s Hawk is seen mostly flying with quick,
consecutive wing beats and a short glide, though they may also soar.
Distribution and Habitat:
Their breeding range extends from southern Canada to
northern Mexico. They are generally distributed more to the south than the
other North American Accipiters, the Sharp-shinned Hawk and the Northern
Goshawk. Birds from most of the Canadian and northern-U.S.-range migrate in
winter, and some Cooper's Hawks winter as far south as Panama.
The Cooper’s Hawk occur in 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 and also
now nests in many cities.They were once thought to be adverse to cities and
towns, but are now fairly common urban and suburban birds. The cities provide
plenty Rock Pigeon and Mourning Dove for the Cooper’s Hawk to prey on.
Feeding:
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. Cooper's Hawks prey almost exclusively on small to mid-sized birds.
Typical prey species include American Robins, other thrushes, jays, woodpeckers,
European Starlings, quail, icterids, cuckoos, pigeons and doves. Birds preyed
on can range in size from wood-warblers to Ring-necked Pheasants. They may also
prey upon the raptor American Kestrel and other smaller raptors, including
their cousin the Sharp-shinned Hawk.
They have been known
to rob nests and may supplement their diet with small mammals such as
chipmunks, hares, mice, squirrels, and bats. Even more rarely, they may predate
on lizards, frogs, or snakes. 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.The hawks, in addition, often pluck the feathers off their prey
on a post or other perch. They have been 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.
Courtship and breeding :
Cooper’s hawks are monogamous and mate for life. Their
breeding habitats are forested areas. The breeding pair builds a stick nest in
large trees. Over a two week period the pair builds the nest. The nests are
piles of sticks around 27 inches in diameter and 6- 17 inches high with a cup-
shaped depression in the middle that is 8 inches across and 4 inches deep.
Their nests are built in pines, oaks, Douglas- firs, beeches, spruces, and
other tree species usually on flat ground rather than on a hillside. The nests
typically are about 25–50 feet high off the ground, halfway up the tree, and
out on a horizontal branch. The clutch size is usually 3 to 5 eggs. The
cobalt-blue eggs average about 1.9 x 1.5 in. and weigh about 1.5 oz. The female
incubates the eggs between 30 to 36 days. The hatchlings are about, 1 oz. and 3.8 in. long and are completely
covered in white down. They 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 larger raptors.
Conversation and Lifespan:
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. The males have a higher
pitched voice than females.
Cooper’s Hawks have been known to live as long as 12 years
in the wild. However, the oldest known living hawk was 20 years and 4 months
old.
Status and Conservation:
At one time, Cooper's Hawks were heavily hunted in
persecution for preying on poultry and were called "chicken hawks".
It is now known that predation by these hawks on domestic animals borders are
negligible, and they are rarely hunted these days. Cooper's Hawks' breeding
success was also reduced by the use of the pesticide DDT, but the ban of DDT
ended that threat. Since then, the adaptable Cooper's Hawk has thrived.
However, one threat facing Cooper’s Hawks today is the degradation and loss of
habitat. Management activities like logging may make their former habitat
unsuitable for breeding.
