Friday, January 26, 2007

My raptor problem, part 37

Part 37? This is the same problem over and over. I still have no eye for the raptors--each identification beyond the few I know in context in which I know them (Northern Harrier flying over a field, Red-tailed Hawk sitting on a post, tree, etc. over a highway in winter, American Kestrel on a wire...) is a struggle.

A neighbour sent me this photo taken in Thomasburg a week ago of what he has tentatively identified as a female Northern Harrier. The white terminal band on the tail in particular makes me think that it is probably a first-year Cooper's Hawk....but I have no confidence in this identification.

Who am I?

Can you help us?

Submitted to the Friday Ark

photo courtesy of Mike Mills


Anonymous said...

I have the same trouble with raptor identification! I'm glad to know that I'm not the only one. ;)

I am inclined to agree with the female Northern Harrier identity, not only from your picture compared with my field guide pictures/descriptions, but also because I saw one just like it in my yard two days ago, perched in a tree, looking down hungrily on the vole munching the birdseed I put out.

The one in your picture looks a little bigger than the juvenile Cooper's Hawk I saw earlier this year on my driveway (eating a bird noless).

I suppose I have an equal lack of confidence in my identification suggestion! Let me know when you'd like me to swing by and muddy the waters again! :D

Good luck,

Anonymous said...

It's a juvenile Cooper's Hawk. Based on what appears to be a slightly rounded (as opposed to squared) tail, the season, and the fact that if that is a standard chain link fence, the mesh is likely in the 2 inch range, making the bird a bit big for a sharpie. In fact, I'd be so bold as to guess it's a female based on the size. Someone with a copy of Sibley's and more patience than I have can discuss the finer points of plumage, but there's no mistaking that accipiter posture and get used to it after you see them more often. Harriers, on the other hand, have a distinctive, owl-like face and very long legs and wings..they're much more frail looking.
Late last week I watched a mature Cooper's kill a pigeon (no small feat, the pigeon not being much smaller than the hawk) only to have the resident red tailed hawk drive it away from the kill. The disgruntled Cooper's then took it's frustration out on a short-eared owl that was hunting over my meadow field, by diving at it a couple of times, and forcing it to ground. The things you see when you don't have your camera in hand.
By the way, Pamela...if you can stand the cold, now is an excellent time to see some snowy owls...there are several on Amherst Island as of now.

John B. said...

It is pretty clearly an accipiter for the reasons J.H. mentioned. A harrier should also have much longer primary projection, with the tips of the wings extending almost to the base of the tail. As for the species, I won't argue with Cooper's Hawk. It is hard for me to judge without being there and seeing the bird from multiple angles.

Pamela Martin said...

JL, stop by any time! John and John explain very well in their comments why this isn't a harrier. I realized reading them that how wings look folded on a raptor was not in my id kit (i.e., long as compared to short)--I hope it's in there now for good.

So, once we know that it's an accipter, given the size (compared to the standard wire fence it's sitting on), not a Sharp-shinned hawk. So, Northern Goshawk? Not big enough maybe, and given the location, it was probably hunting the house sparrows that hang out in a nearby hedge, smaller prey than the goshawk prefers, a tasty snack for a Cooper's.

John H., thanks very much for the identification and tips. And for the fantastic raptor scene you described!

I know the facial disks of the harrier--look for them whenever I see one, but it has seemed to me that you need a sighting at just the right angle to see them, then they jump right out as the owliest looking hawk imaginable.

I think that Quinte Field Naturalists are making a trip to Amherst in February--maybe if the timing is right I'll ask if I can tag along. Not such a big twitch, and I would like to see a snowy and all the other owls I keep hearing about down there.

DC John, thank you for the very clear statement about the look of the folded wings of the long-winged compared to the short. I think I've got it now. I hope so.

Lynne at Hasty Brook said...

I felt sure it was a Cooper's but the two Johns' explainations of why were terrific!!

PolarBear said...

Definitely a Cooper's Hawk - it is my first time saying anything on this blog but I was about to launch into an explanation when I saw others already had.

My brother, who lives in Oshawa, had one in his backyard a few weeks back, too. I lingered long over my field guides to make an identification.

Anonymous said...

Though Red-tails are far and away the most common hawks in the northeastern US (and everywhere else in the US if I'm not mistaken), I get the impression that Cooper's are the ones photographed most often in people's backyards and submitted for identification.

Could the Cooper's Hawk be the Song Sparrow of the raptor set?

Pamela Martin said...

Lynne, yes they were--and while field guides are indispensable, there's nothing like a personal account from another birder to inspire confidence, and help get a bird properly in mind.

Polar Bear, thanks for stopping by, and for adding your voice. The wild is really permeating the urban--a Cooper's in an Oshawa backyard! Wonderful!

Pamela Martin said...

Mike, I think you've got something there. One reason I was hesitant to boldy assert that this was a Cooper's was that it was starting to seem like all raptors were Cooper's, and that didn't seem right. Just as it is easy to think that all streaky sparrows are Song.

I suspect the reason for all the Cooper's though is that they are big fans of bird feeders, whereas Red-tailed Hawks like bigger prey, and bigger spaces.