Cooper's or Sharp-shinned hawk?

[Julie Brown]

Image made 10/12/11 at Matheson Preserve, Moab, Utah.

I keep going back and forth from the field guides to the monitor, and just can't figure out which Accipiter this is. Does the white tipped tail mean it is a Cooper's? Thanks for any help!:tinysmile_shy_t:

[P-A. Fortin]

Tough call, especially since I am _really_ bad at hawk identification.

However, the tail end looks pretty much square to me. Also the legs look a bit small (Cooper's are supposed to be thicker).

So I'd go for Sharp-shinned. But that's just me throwing in a wild guess. Just wait for Paul or John to show up and tell me I am wrong :bg3:

[Dan Brown]

Tough one! I would go with Sharp-shinned also, based solely on the thin white band at the tip of the tail. Cooper's should have a much wider white band at the tip of the tail. But..........?

[Julie Brown]

Hey P-A. and Dan, so far you guys are confirming my initial feeling that this is a Sharpie. I have a side-view of this bird as well. What about the placement of the eyes in the head, or the color of the crown feathers?

[Julie Brown]

Here is a side view. The head does not appear to have "cap" like the bird in Pat's post. Or it may just be different light.

[Dan Brown]

To me, this photo looks even more like a sharpie than the OP. The tail really looks good here.

[Roy Priest]

Side view confirms, to me, it's a Sharpy.

[pat lillich]

Julie, I'm so glad you posted this sharp-shinned right now too -- it really is easier to see differences with the two birds right here - Isaac's comment about the eye is really interesting - your bird's eye seems less hooded than the cooper's eye is (the "cap" effect you mentioned. ) I would love to see their skulls side by side - I know a college website with 3d scans of many skulls and skeletons - I think i'll go look see if they have both of these birds.

[Julie Brown]

Hi Pat. That would be interesting to see the skull comparison. If you find it, let us know the link.

We had good timing with these posts. It is so nice to have the resource of expert birders to draw from. These two Accipiters have always caused confusion for me, but I feel a bit more confident now in knowing what to look for.

[pat lillich]

hey Julie - I really appreciate the kindness of the experts here in helping me learn. i'm just starting out on learning the different birds, so i need all the help I can get.

Digimorph doesn't seem to have the skulls of either bird (I'm more used to looking for mammal skulls) - but skullsite had both...
sharp-shinned : http://www.skullsite.com/completelist/speciesinfo.cfm?spec=565
coopers : http://www.skullsite.com/completelist/speciesinfo.cfm?spec=508

looking at the eye area especially, the sharp-shinned skull is much more delicate and as Isaac said - the proportion of eye to skull is much greater. and as he said, the bone around the coopers eye is much heavier

this page shows the skulls side by side (though unfortunately they aren't both at the same scale) and you can really see the difference in the shape of the orbital areas : http://www.royalbcmuseum.bc.ca/Natural_History/Bones/Skull/skull48.htm

[Isaac Green]

Pat, love the skull site. Thanks for pointing out that great resource.

[Julie Brown]

I bookmarked those links. Really interesting to see the comparisons. Thanks Pat!