You're very fortunate to have a hawk in your yard, and to be able to see it
make a kill is quite unusual. A batting average of .200 is considered good.

We have an immature female cooper's hawk as a regular visitor and feeder
upon our many visiting pine siskins. We named it Alice before having read
Dan O'Brien's Equinox. They seem to be increasing in our area (NW Whatcom
County). There is a nesting pair now in Cornwall Park in Bellingham.

In our experience with Accipiters (from a Latin root meaning "to take unto
one's self," as in shoplift or swipe), the question of sex is easier to
answer if you first confirm the species.

Hope that isn't an insult, but it's a method that has worked well for us
because the sizes overlap, that is, the females are larger in both, and
the female sharpie can be bigger than the male cooper's. A male sharpie is
tiny; Bud Anderson has a slide of one perched comfortably with both feet
outside the last knuckle on his index finger. A female Cooper's can be
bigger than a crow, esp. our crows.

So, which species do you have? These two are quite similar. Perching out on
a rail or post is a cooper's habit. Sharpies tend to stick to trees. If
you get a good look again, look at the leg thickness (cooper's are the size
of a pencil, sharpies' legs are thinner and more delicate). Also, cooper's
have an obvious break in the color between the top of the head and the
back, as if they're wearing a cap, cooper's cap. Sharpies are smooth from
head to back in color, sharpie smooth. Cooper's have a definite notch at
the cere (e.g. base of the beak & forehead make a notch) but sharpies are,
again, smooth, having a much smoother line from the beak of the top of
their heads. Cooper's has a tail in which the black bands sometimes look a
little askew, and the white band on the aft (distal) edge is quite a bit
wider than on the sharpie, whose tail bands look more neatly aligned and
whose white tail band is limited to just the edge. We always look for the
"cap" and have found it to be a reliable tip-off.

Also, if it doesn't gross you out to do this, surf a little on some of the
internet "Falconry" pages and look at some of the beautiful and very close,
detailed photo's they have of all kinds of raptors. It gives you a
good look at some interesting detail.

Then, the size will tell you the sex. If it's big, it's a female. What
"big" really means is a lot easier to judge once you have a species:
Roughly (check your bird book), a male sharpie is really little, close to a
robin. A female is closer to a pigeon. A male cooper's is about the same
size, give or take, and a female cooper's is the size of a crow.

Enjoy the air show!



Jack Kintner kintner at nas.com Blaine

> Lately we have a new visitor, a SHARP SHINNED HAWK, who I've come to
> think of as the neighborhood assassin. It has been a passing visitor for
> about three months that we have noticed but this weekend he seems to have
> moved in permanently. I say he with reservations. Despite several
> close looks with time to compare the view in the binocs to Sibley we got
> as far as an adult bird. Have not a clue how to sex it. Any help there
> would be appreciated. Anyway, Saturday morning we had the usual 30+
> grosbeeks feeding and then roosting in the leafless alders at the back of
> the property. Something came in very quickly and made a couple of fast
> circles around the roost trees and then snatched a grosbeak which was
> slow to take off. Our assassin was making himself at home. (I say
> assassin in a joking way. He is doing what mother nature designed him to
> do. Thinning out the weaklings and keeping the local population healthy
> and on it's toes.) About an hour later this bird actually lit on the
> rail around the back deck under the Siskin feeders. This put it about
> ten feet from where I was sitting. I sat very still and was rewarded
> with about three minutes of close up viewing. It then went to the edge
> of the property where it maintained a vigil over the yard feeders and the
> local runoff pond behind the property. We get a few mallards and some
> Canada's down there. Three hours later it again appeared on the deck
> inspecting something on a piece of ground which I could not see. It
> finally hopped down and grabbed an apparently dead grosbeak which I had
> not seen and departed. This bird was seen in various observations points
> around the area the rest of the weekend. I'm curious to see how it's
> presence changes the feeding habits of the local birds.