Grays Harbor Birds - Cooper's Hawk


If you happen to have bird feeders hanging in your yard, you have probably seen a Cooper’s Hawk. They have an uncanny knack of finding the feeders in a neighborhood and lurking nearby to take advantage of fairly easy prey … your feeder birds.

The difficulty is distinguishing a Coop from a Sharp-shinned Hawk; they are both likely to be in the neighborhood. A female Sharpie is about the same size as a male Coop, and both have the same feeding habits. Both use the flap-flap-glide method of flying unless chasing down prey, when they are able to dodge branches and other obstacles in their chase through trees. The Cooper’s head is larger and juts farther forward of their wings when flying, and they have “hackles” that can be raised on the back of their head, giving them a fiercer look. An adult Coop also has a lighter-colored nape making it look as though they have a dark cap. When perched, you can see a Coop has thicker legs than a Sharpie, and a Coop’s tail is more rounded when folded, and longer than a Sharpie’s.

All that is helpful, but normally the sighting is very brief and very fast, so it just takes a lot of time and patience to distinguish the two. Gregg Thompson’s photo shows most of those characteristics. Here are more facts on these exciting birds.

Size: A female Cooper’s Hawk is 16.5 to 17.7 inches long, with a wingspan of 29.5 to 35.4 inches, and weighs 11.6 to 24 ounces. A male is 14.6 inches long, with a wingspan of 24.4 to 35.4 inches, and weighs 7.8 to 14.5 ounces. That is a lot of difference! An interesting fact is Cooper’s Hawks from western North America are substantially smaller than birds in the East, weighing about one-fifth less than their eastern cousins.

General Description: The Cooper’s Hawk is the most widespread of the three North American accipiters. A medium-sized hawk with broad, rounded wings and a long tail it uses like a rudder to maneuver through the trees, it is about the size of a crow. Adults are a solid gray on their upper parts and their breasts are white with reddish-brown streaks. Their tails have gray and black barring, rounded ends, and a bit of white at the tip. The eyes of an adult are red and their legs are yellow. The immature birds have brown upper parts, brown streaking on their white breast and belly, and yellow eyes. The eyes are set facing forward, enabling good depth perception for hunting and chasing prey while flying at top speed, and they have small, hooked bills for tearing the flesh of their prey.

Habitat: Long a bird of mature woods, the Coop prefers hardwoods and forested edges, but has found a new niche in our wooded back yards and urban and suburban parks. It needs tall trees for nesting, but has adapted well to our changing woodland landscapes.

Behavior: When hunting, the Cooper’s Hawk is a stealthy predator, quietly moving through dense brush and trees until it can make a fast burst of speed to catch the prey unawares. It will also fly fast and low to the ground, then up and over an obstruction to surprise prey on the other side. It kills by squeezing with its powerful feet, and has even been seen holding its prey underwater until the prey quits moving. One study showed their dangerous style of hunting takes a heavy toll on their body, with over 300 Cooper’s Hawk skeletons showing 23 percent of them had healed fractures in the bones of the chest.

Diet: The majority of the diet is made up of medium-sized birds, such as doves, jays, robins, starlings, and pigeons, and squirrels and mice. Courtship and Nesting: A male Coop’s courtship can be dangerous as they are smaller than their potential mate, and a female Coop’s food is usually a smaller bird. So it is important for a male to read the signs correctly when proceeding with courtship! He listens for reassuring calling from the female indicating she is willing to be approached. Cooper’s Hawks are monogamous, but most do not mate for life. The displays include stylized flights, with the male first diving toward the female, then a slow-speed chase while the male shows off his expanded under tail coverts (the feathers at the base of the under tail). He will often raise his wings high over his back and flap slowly in a wide arc around the female. Courtship can last a long time, and the male will often feed the female for up to a month before mating. The pairing usually occurs on bright, sunny days, and ends with him making a bowing display before beginning to build the nest. It is usually is 25 to 50 feet off the ground, in a tree on a flat location, and may be on top of an old nest or clump of mistletoe, fashioned of sticks and lined with pieces of bark. The pair incubates three to five eggs for 30 to 33 days, with the male sharing nest-duty when the female eats.

Once the eggs hatch, the female broods the nestlings for about 2 weeks, with the male bringing food to the nest and the female feeding the young. At the age of 4 weeks, the young begin to climb around the nest and then begin branching (moving about on nearby branches) and making short flights soon after. Both parents continue to feed the young for up to 7 weeks.

Migration Status: Most of the Cooper’s Hawks of Washington migrate south to central and southern Mexico for the winter, but are replaced by birds from farther north, so we have this bird available to see most of the year.

Conservation Status: Populations in the west seem to be fairly stable, thanks to the banning of DDT, but as usual the main threat is habitat loss. Because they are difficult to observe, it is hard to get a clear picture of their status.

When and Where to Find on Grays Harbor: They are hard to spot because they are reclusive, but if you have feeders you probably have Cooper’s Hawks in the neighborhood. It just takes patience, and a comfortable, warm place from which to watch your feeders. Be careful though, birding can be addictive.

 

Rules for posting comments