Crow Confusion (1 Viewer)

[GaryT]

Would anyone like to comment on the species of crows in the attached photo? The one on the bottom was photographed in Pennsylvania and is clearly an American crow. The one on the top was photographed just south of Lincoln City, Oregon, well outside of the range of the northwestern crow. Hard to believe these are the same species. Consider that the northwestern crow is supposed to be hard to tell from a common crow. Gary

 

[ovenbird43]

There is some regional variation in size and voice in the American Crow. The American Crows in coastal Oregon are smaller and have higher-pitched voices than the "typical" American Crow.

 

[birderbf]

Some evidence suggests that the Northwestern Crow and western subspecies of American Crow are more closely related than the western and eastern subspecies of American Crow. But still, that's genetics. They're practically identical in plumage and structure. Why do you find the two crows pictured strikingly different?

 

[MLoyko]

I don't see anything different except for the head shape but that is probably because of the top one'sneck being in a retracted position.

 

[Kratter]

Most of the differences I see are due to differences in molt and wear. The top crow is in active wing molt and has the fresh inner primaries and greater primary and secondary coverts (the glossier black feathers on the wing), but old outer primaries and secondaries (the flat black feathers). Most of the body plumage is worn. The bottom bird appears to be in complete fresh plumage. The back feathers are crisp with a slightly darker fringe, giving a scalloped look. In 6 months or so the entire plumage will be flat black like the bird above due to wear and bleaching by the sun.

Although the field guides would have you believe that all individuals should look like the one pictured, even birds of the same age, sex, and population can look strikingly different due to differences in molt.

Andy

 

[GaryT]

I am amazed you don't see much difference! Look at the difference in the length of the legs and the size of the feet -- this is not just a matter of stance. Body size and shape and the position of the eyes differ greatly as well. The only similarity is that they are both black. Perhaps I have the advantage of having actually seen the birds. I was very surprised by how much the Oregon crows differed from the crows here in the East when I first saw them. That is why I took the photos. Of course, it is a matter of genetics. I guess this thread really belongs in the taxonomy forum. Sorry about that.