On Sep 11, 2009, at 3:53 PM, Geoff wrote:

> If the hawk was engaged in a "tussle" with a kestrel, its a
> sharpshin. If the hawk was a coopers, it would have been an attempt
> to eat the kestrel, although I suppose that could also have been
> described as a "tussle" as well. Coopers hawks eat a lot of kestrels.
>
If the accipiter caught the kestrel on the ground or perched in a tree
it would eat it. Sharpies and Coopers are ambush hunters. They're not
going to take a bird (especially a Falco) in flight though a juvinile
might attempt it.

I suspect the behavior was the other way around. The kestrel was
harassing the accipiter. I did ask the OP but didn't get a reply.
> Wether its a sharpshin or a coopers cant be determined by the photo,
> but would be easy to determine by comparing the size to the
> kestrel. A coops would be 30-60% larger than a kestrel, and a
> sharpshin would be about the same size as a kestrel.
>
But the hawk in the photo is doing something interesting: it has
turned its head to look over its left shoulder. It's cranked it right
around.

A (no neck bowling pin) Sharpie can't do that. But a Cooper's can.

This behavior is mentioned by Peter Dune in Pete Dunne's Essential
Field Guide Companion. Which has plenty of other non-fieldmark
("jizz") ID tips for every US species and no pictures! A handy book
for stuff that plenty of good birders know but can't always verbalize
to pass on to others.

The bird photographed is a juvenile (white spots on the back) Cooper's
Hawk.
--
Kevin Purcell
kevinpurcell at pobox.com
twitter: at kevinpurcell