On Sun, 28 Sep 1997, Michael Brown wrote:

> My yard was raided this afternoon by what I finally decided
> (half-heartedly) was a juvenile male Cooper's Hawk. It sat on the
> neighbor's fence eating what appeared to be a female House Sparrow.
> never felt sure.
[description snipped]
>
> How do people ID them with brief glimpses in flight!? Geeezzzzz!

I agree with what Rob Saecker said: after the first several hundred, the
differences become clearer. Heck, I remember when I was new to birding,
studying a sitting immature hawk in Michigan for over an hour, unable to
decide if it was a Coopers or a Red-shouldered!

But also, sitting hawks can be deceptively hard. As Kenn Kaufman points
out, the best (subconscious) clue to size we have on most birds is their
mode of flight, that is, how fast they beat their wings or how "heavily"
they fly. You don't have that with a sitting bird, so unless you have
direct comparison with a close bird in the right size range, it's hard to
get a feel for exactly how big it is. And since many of the differences
between accipiters are structural, getting a close up look at a sitting
bird doesn't always help all that much (although you could check the
chapter on accipiters in the Peterson Guide to Advanced Birding for a good
summary of plumage details).

And finally, if you get only a brief glimpse before a flying accipiter
disappears, it's harder for someone to contradict you if you confidently
yell out "Male Cooper's!" ;)

This is a great time of year for unusual yard birds - I had a sharp-shin
(about the third since moving here two years ago) bounce off the window
yesterday, apparently without damage to itself.

Chris Hill
Everett, WA
cehill at u.washington.edu