Bird Filter - What kind of raptor was that?

January 11, 2009 8:34 AM

While on a walk in the dunes yesterday, I saw what was clearly a raptor, but not one I had seen before. It had a rust-colored breast with dark wings and a dark tail. It was smaller-bodied than a red-tailed hawk and the tail was on the long, slender side. I did not see any bar markings, and it did not appear to be a Cooper's Hawk or a Sharp-shinned Hawk, and that's the extent of my area hawk knowledge. Some sort of falcon, perhaps?

I am located on Cape Cod, Massachusetts, it was mid-day in the beach dunes, and the area is heavily populated by rabbits (if that helps).

Naturally I tried Google, but did not come up with a picture that looked close.

Any ideas?

posted by coollibrarian to science & nature (8 comments total)

Could it have been a peregrine? They can, but don't always, have rusty chests.
posted by dilettante at 8:54 AM on January 11

Can you describe its behaviour? Was it sitting, hovering or scanning? Did you see it dive or hunt at all? That may help nail it down.
posted by Brockles at 9:13 AM on January 11

A couple of caveats, which you may already know: light conditions and distance can wreak havoc on identification.

So. Was it flying low and slow? Northern Harriers hunt small mammals, snakes, and even small ducks in grasslands and marshy areas. Adult females are striped on the breast, but that may be hard to see, and they are buffy (may appear reddish) on the underside. Juveniles of both sexes are pumpkin orange underneath. I have seen harriers that fooled me - it's a Coop! No - peregrine! No - 'tail! No...harrier.

Redtail is probably the most likely; I impress my friends my IDing raptors while driving (I'm driving, not the hawks), but a lot of it is just statistics - a raptor that's doing X, Y, and Z, and is approximately Y size/shape is overwhelmingly likely to be a redtail, so I'm going to be right at least 8 times out of 10.

Redtails come in a huge range of plumages - there are dark morphs, rufous morphs, light morphs, etc. And the juvenile will not have a red tail.

If you can give more detail about how it was flying, that might help. And if you can get hold of Hawks From Every Angle, the photos there might give you some guidance.
posted by rtha at 9:29 AM on January 11

Red Tails are abundant here and I see them all the time - I don't think it was a red tail. Too small and thin, even for a juvenile.

Peregrine was my next guess, though Northern Harrier looks interesting.

The bird was in flight, low and slow, looked to be scanning. I basically saw it from a side angle, so I did not see if there was a pattern on it's chest or under the wings - just that the chest was definitely rusty and the shoulders dark. The tail was dark and long, not fanned. It was 2pm and bright out, and I was no more than 100 feet away. I did not see it land, though it was headed for a clearing where there were many bunnies hanging about.

I will see if I can find that book, rtha.
posted by coollibrarian at 9:50 AM on January 11

Low and slow makes it 99% likely to be a harrier. Peregrines hunting for ground food (as opposed to birds) will fly swiftly and fairly high over a field; redtails will hover or still when hunting ground prey on the wing; harriers cruise very slowly and no more than four or five feet off the ground (and often lower), and can turn on a dime. They have a fairly distinctive white rump patch, although it's not always visible. If you get a look at the face, they look kind of like owls because of the way their feather are set around their eyes and ear openings. They have long, slim wings, and a long tail.

If the topside looked more brown than blue, it was unlikely to be a PEFA, since even female PEFAs look more blue-grey than brown, and the males are very definitely slate blue. Male NOHAs, btw, are also known as "grey ghost", because they are a gorgeous silvery grey, with black wingtips.
posted by rtha at 9:59 AM on January 11

rtha, thanks for the information! I will keep all of that in mind when I am out on my walks. I am used to seeing red tails and osprey (I live on a river near the ocean, so there's tons of osprey here), but I am hoping to expand my raptor sightings this year.
posted by coollibrarian at 10:06 AM on January 11

Anytime, coolibrarian. Pick up a copy of Hawks from Every Angle, and a Sibley field guide (the East coast edition, obv), and hook up with your local Audubon - the easiest way to learn how to ID birds is to hang out with more experienced birders - questions like "How did you know that was a [name of bird]?" are welcome and will usually garner more information than you really wanted!

And anytime you happen to be coming to San Francisco, we'd be happy to take you around and show you some Western raptor action.
posted by rtha at 10:42 AM on January 11

If it helps here's the Wellfleet Audubon's list of common Cape Cod hawks by species.
posted by nicwolff at 3:48 PM on January 11