[CT Birds] Accipiter ID

Joseph Cala joseph.e.cala at gmail.com
Mon Jul 21 18:05:17 EDT 2014


I was waiting for one of you hawk-watchers to chime in and question the
ID.  :)

You're absolutely correct that it's not a clear cut bird by any means.
This particular bird has quite a few things going on that makes the ID
harder, and the fact that you're dealing with male Coop/female Sharpie
makes the ID even more difficult.

I absolutely agree that the bird is in a state of molt -- it's a juvenile
molting into it's first adult plumage.  I also agree that the tail is long
-- which compared to body size is another point for Cooper's Hawk.

The head looks large, to me, and there is much more projection then I'd
expect for a Sharpie.  Of course both of those items are 100% subjective
unless you're looking at a small male Sharpie or a large female Cooper's
Hawk -- some birds make it easy, others don't.  I don't think that trait is
diagnostic unless you're at either extreme of the spectrum.

The wing shape/position can be tough - especially when you're dealing with
two photos instead of watching the bird.  I'll be completely honest -- I
hate accips in flight.  I find them to be 100x tougher than perched birds.

The streaking, however, is something I'll go to bat on as being one of the
most useful field marks on juvenile Accips.  Of course there's variation,
and some Cooper's hawk (especially in the west) are definitely in the range
of Sharp-shinned, and there's also Sharpies that show reduced streaking,
but it's certainly a very valuable field mark that I don't think should be
tossed aside because it can be variable -- almost all field marks can.

The last several points you make are valid ones, and ones that I'd expect
from a seasoned hawk-watcher.  You all have much more experience with wing
shape and 'behavior (ie flight style, wing beats, etc) and can use those
skills to readily ID birds flying by--when they're too far away to see
plumage details.  I think on the flip side we need to be cautious when
IDing from pictures in the sense that just because we didn't see the bird
fly doesn't mean we can't make a solid ID.  It might make the ID more
difficult, but most birds can be ID'd from decent photos.

The bird was photographed recently in Boise, Idaho.  Quite a few Cooper's
red dots on the map in that area, not a single for Sharpie.  Of course
that's a double edged sword in assuming that others have made correct ID's
on these species.

I'm very confident that based upon the streaking, head size/projection,
tail length, unstreaked throat, etc...that this bird is a Cooper's Hawk.  I
understand that with 'tweener' birds like this there will never be a 100%
agreeance and that's fine.  The debate is always fun, though.

Definitely look forward to seeing some of you at Lighthouse Pt this
fall--just don't ask me to ID anything flying by.  I'll stick with hiding
behind my camera -- raptors in flight without photos are not a strong suit
of mine!

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