[Tweeters] Dan Schurman's Hawk Photos

Bud Anderson falconresearch at gmail.com
Sun Oct 10 12:56:33 PDT 2010

Hi Dan,

As people have commented already, that is a really nice group of photos.

This bird is definitely an immature male Cooper's Hawk hatched out this
summer, perhaps locally.

So you know, I base this opinion on the following five features.

1.) In your first photo, you can clearly see the diagnostic head profile.
Cooper's Hawk heads, especially in profile, are totally different than
Sharpys. COHAs have a beautiful, smooth sloping profile (similar to a Golden
Eagle), uninterrupted by the slight "forehead" above that cere that is so
typical of SSHAs.
2.) The eye is much smaller in proportion to the head than a SSHA. In
comparative in-hand shots, you will see that both female SSHA and male COHAs
have about the same sized eye. This characteristic makes the eye look much
smaller on the head of a COHA.

3.) As mentioned by others, the outer tail feathers are much shorter than
the central or "deck" feathers, which is one of the classic field marks for
COHA but not always so clearly apparent as in your excellent shots. In fact,
unlike SSHAs, the outer or "guard" tail feathers are usually about 12mm
shorter than the decks in COHAs.

4.) The thickness of the tarsus makes it a male. The thickness of the
female COHA tarsus is generally about the same diameter as a pencil. Males
approach the matchstick size of the SSHA but in this bird both the thicker
tarsus and the thickness of the middle toe eliminate SSHA. In fact, this
bird really has a slightly unusually thick toe for a male COHA .

I also find the white throat with a central dark vertical line pretty
unique and really, kind of gorgeous.

5.) And BTW, I was just discussing your photos with my friend and local
accipiter expert, Jack Bettesworth, and he pointed out another feature to
me. This bird has some slight streaking on the crissum or undertail coverts.
Jack never sees this in SSHAs.

Hope this is of help....

Bud Anderson
Falcon Research Group
Box 248
Bow, WA 98232
(360) 757-1911
falconresearch at gmail.com
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