Thursday, September 17, 2009

Juvenile Sharp-shinned Hawk

Sharp-shinned HawkJuvenile Sharp-shinned Hawk, Beaverton, Oregon on 9 September 2009 by Greg Gillson.


On a recent outing I spotted this bird fly into a tree in Beaverton's Greenway Park.

Many birders, including many experienced birders, have trouble separating the two regular lowland Accipiters, or "bird hawks." Cooper's and Sharp-shinned Hawks are notoriously difficult, as there are very few differences in plumage and structure. The small male Sharp-shinned Hawk (10 inches) is shorter than a jay (11 inches). The large female Cooper's Hawk (20 inches) is longer than a crow (17 inches). The female Sharp-shinned Hawk and male Cooper's Hawk are the same size--about like that of a Band-tailed Pigeon (14 inches). Obviously, estimating size of lone birds has its pitfalls.

Adult Accipiters have red-barred chests, while the juveniles show brown streaks. In the autumn, there are many juvenile birds, doubling the population. Accipiters migrate in September and October, bringing view of them circling in the sky over head, or to your backyard feeders where they prey upon your seed eating birds.

With short, broad wings and a long tail, these birds fly deftly through the woods at high speed. They eat smaller birds and squirrels.

So, what ID marks are present on this bird? The eye is in the center of the head, good for Sharp-shinned Hawk. On the Cooper's Hawk the eye is more toward the front of the head. And the tip of the tail on this bird is obviously squared or notched, not rounded, also a tell-tale mark for Sharp-shinned Hawk.