Cooper's or Sharp-Shinned Hawk? (2 Viewers)

[GuyScharf]

I saw this hawk sitting on the back fence where we are staying in San Clemente, CA. I went to get the camera. As I raised the camera to take the photo, it flew, so this is the only photo I have (and it's blurred). For sizing, I presume the spacing between the vertical bars is the standard code-compliant 4 inches.

As I saw the bird sitting from the back, it was mostly gray, long tail, with some bars across the tail. Looks like it would be either Cooper's or Sharp-Shinned?

Thanks!

Guy

 

[carol gbh]

Can't be sure

>>>>>>As I saw the bird sitting from the back, it was mostly gray, long tail, with some bars across the tail. Looks like it would be either Cooper's or Sharp-Shinned?<<<<

The two things I notice that help determine this difference are both absent from this photo - the Coopers has a thicker white terminal band (which is not seen in this photo) and a rounded tail - the Sharpie has a square cut tail. Coopers are considerably larger and have a longer tail as well. But I think the best clue here is that this bird was sitting on a post n'est pas? You almost never see a Sharpie do that. Also Coopers undertail coverts are entirely white - another clue.

I'm new here and was looking at the thread on the merlin/peregrine with 2 godawful pictures. I would never have guessed merlin - for the same reasons as here - they perch high up for the most part - and not on fence posts. but this is general. I worked with captive breeding peregrines - and would not have guessed peregrine either.


Carol in CA

bird by intuition - and this might be a Coopers

 

[AlexC]

I dunno... those legs look pretty thin to me. And a roundish head... but it really is hard to tell b/c it's taking off. *Prepares to be shot down* I'll say Sharpie. BTW, though it may not be great for an ID, Guy, this pic is really cool!

 

[Katy Penland]

Cooper's for me. I considerably lightened and slightly sharpened the photo. You can see the clean undertail coverts. But more importantly for me was the size. If those fence verticals are 4" apart, this would have to be Cooper's. Sharpie's are 11" long. This bird, foreshortened by the angle of the shot, is longer than this even at this angle.

 

[JANJ]

That´s better Katy,
and the obvious contrast between darker crown and neck/sides.
JanJ

 

[snowyowl]

>>>>>>As I saw the bird sitting from the back, it was mostly gray, long tail, with some bars across the tail. Looks like it would be either Cooper's or Sharp-Shinned?<<<<

The two things I notice that help determine this difference are both absent from this photo - the Coopers has a thicker white terminal band (which is not seen in this photo) and a rounded tail - the Sharpie has a square cut tail. Coopers are considerably larger and have a longer tail as well. But I think the best clue here is that this bird was sitting on a post n'est pas? You almost never see a Sharpie do that. Also Coopers undertail coverts are entirely white - another clue.


Carol in CA

bird by intuition - and this might be a Coopers

I id.'d this bird as a sharpie without giving it alot of thought but now I'm wondering. A Cooper's would be pretty unusual in my area. The streaking on the breast seems typically sharpie but from what you've said the behavour would be very out of character?

 

[lou salomon]

sharpie allright for me. no blackish cap, regular coarse barring on underparts, thin feet.

 

[atricapillus]

I saw this hawk sitting on the back fence where we are staying in San Clemente, CA. I went to get the camera. As I raised the camera to take the photo, it flew, so this is the only photo I have (and it's blurred). For sizing, I presume the spacing between the vertical bars is the standard code-compliant 4 inches.

As I saw the bird sitting from the back, it was mostly gray, long tail, with some bars across the tail. Looks like it would be either Cooper's or Sharp-Shinned?

Thanks!

Guy

________________________
Looks like a 3-3 tie so far.

On basis of tail, I would say Sharpie. No (almost no) buff tips, outer tail feather same length (near same length) as next one in, and the rest for that matter. The angle isn't great, but it looks proportionately short tailed.
Cap color nudges down around eye, so not particularly capped.
my 3 cents.
CHEERS, JOE G

 

[birdpotter]

I am going to anti up and give my four cents...
I say sharpie too. Even though the angle isn't that great, the tail looks too short for cooper's. Head seems to be fairly rounded too.

 

[lou salomon]

________________________
Looks like a 3-3 tie so far.

On basis of tail, I would say Sharpie. No (almost no) buff tips, outer tail feather same length (near same length) as next one in, and the rest for that matter. The angle isn't great, but it looks proportionately short tailed.
Cap color nudges down around eye, so not particularly capped.
my 3 cents.
CHEERS, JOE G

i was referring on snowy owls latest pic for sharpie. the original bird is a coopers.
cheers,

 

[Tero]

Going by the rungs and the angle, it seems to be up to 14 inches long. Still not ruling out Sharpie by size.

 

[snowyowl]

Sorry, my post seems to be confusing the thread.

 

[Katy Penland]

I'd say your pic, Dan (Snowy Owl), was a Sharpie, too. Note the thin legs (tarsus) and evenly broad breast/belly streaking.

I wouldn't put too much stock in trying to ID a bird solely by its perch. I've had Sharpies and Cooper's sit on everything from chimneys, fences and fence posts, telephone poles and wires, but mostly trees, and in both urban and rural settings. It seems they use what's available.

 

[JANJ]

I wouldn´t put to much stock in trying to ID a bird soley by its perch

I'd say your pic, Dan (Snowy Owl), was a Sharpie, too. Note the thin legs (tarsus) and evenly broad breast/belly streaking.

I wouldn't put too much stock in trying to ID a bird solely by its perch. I've had Sharpies and Cooper's sit on everything from chimneys, fences and fence posts, telephone poles and wires, but mostly trees, and in both urban and rural settings. It seems they use what's available.

I wouldn´t either.

JanJ

 

[GuyScharf]

Thank you all. These discussions are always illuminating to me.

I'm chalking this one up as a Cooper's especially because of size, as Katy pointed out.

Guy

 

[Thayeri]

Ah, but Katy was (with all respect) likely taking her size directly from Sibley, and not accounting for sexual dimorphism, which is strong in Accipiters. Sibley says 11 inches, but that is only an average, the real range is (per Wheeler’s far more detailed information) 9-11 inches for males, and 11-13 inches for females. I have seen many male and female sharpies at a local raptor banding station, sometimes held side by side, and the males can look more like prey for the females than the same species, the size difference can be so great. We see about 11 inches in the photo from a bit of a side angle, and I think this could be a 13 inch female.

The photo makes it tough, but my vote is for sharpie, based upon the following:

1) small bill size
2) smallish, rounded head
3) darkish auriculars,
4) no sign of a pale nape (using a lightened and sharpened photo to determine true contrasts would be chancy indeed)
5) small, thin legs and feet
6) Squarish looking tail feathers, with no sign of the outer ones being of lesser length than the inner ones
7) No white terminal band on the tail
8) The tail looks on the short side, even accounting for angle

Overreliance on any one feature with accipiters is dangerous, but with all eight of the above I feel pretty good about saying sharpie, even with the odd angle and challenged lighting.

The second bird also looks like a sharpie to me.

 

[GuyScharf]

What book is "Wheeler's"?

I don't remember seeing a white band on the tail, but I was focused more on getting the camera than on details. It did strike me that the tail was squared off.

Guy

 

[Katy Penland]

Re: Thayeri's post...

Lightening the photo overall will not compromise relative contrast between light and dark (I didn't touch the "contrast", only "brightened" the whole image using Photoshop Elements). In the same lightened shot as before (with no further lightening or sharpening), I've outlined in red the obvious dark cap and lighter nape on this bird. (Please pardon the squiggly line, my mouse sucks at drawing.) Sharpie should show the nape area as the same color as the cap, but this bird doesn't -- it's clearly lighter. I'm also not seeing the auriculars as any darker than the rest of the side and nape.

I did use both my Wheeler's "Photographic Guide to NA Raptors" (for images) and Sibley's (for the average size). I agree with Thayeri, there can be extremes in sizes, but I also have to take exception to this being a 13" bird. I'd guess that the angle of the bird flying away from the fence is somewhere between 30-45 degrees, meaning a 30-50% margin for error in estimating its actual length (using a 90-degree angle of incidence, with the fence being 0 degrees and taking off straight away from the fence [and the camera] would be 90 degrees). The bird, without angle taken into account, is, using the verticals, 2", 4", 4" and 1-2" long = 11-12". Assuming even a 30% adjustment for angle, and you're looking at a bird that's 14.3-14.6" at a minimum, well beyond female Sharpie range. But I'm just guesstimating the angle and you may not agree with that guess.

The relative length of the tail feathers to each other can only be compared on the folded tail, not fanned, especially where the angle of the shot is of no help.

For Guy's question, I've used little carats to point out the white edging where it can be seen against the dark feather behind it. But the amount of white is not empirical for either species as wear can play a big part in how wide this band is. To answer Guy's other question, the Wheeler guide I use is above; Thayeri may have been referring to that one or the "big" Wheeler which is more of an encyclopedia.

But as I always say, I suck at photo IDing. :t:

 

[atricapillus]

Well, the vote (or leaning toward) tally right now is 5-4 in favor of Sharpie, with long discussions supporting each. I am probably weighting too much on the tail, but there is not much tail past the undertail coverts (so relatively short), and the 5th and 6th feathers in from the left (the midde ones on a tail) look as long or slightly shorter than the outermost. These SSHA /COHA threads can typically go a while, but I remain with Sharpie (although JanJ has been reliable enough in the past to make me nervous).
CHEERS, JOE G

 

[Miedin]

At first glance this looks like a Cooper's with the appearence of the dark cap but the smallish head and beak with the square tail say Sharpie to me. I can't say for sure but my oppinion is Sharp-shinned Hawk.