Serge wrote:

>yesterday, I saw a weird Crow, with a hook-like bill (let's call this
>guy _Corvus caurinus paulsoni_).

I resent your allusion to my nose--and you haven't even seen it!

>He was on a gamefield with some others (regular) corvid pals.
>I looked at it for five minutes, because I was just curious how it could
>feed with such a non-crow beak.
>It quickly caught an earthworm, but I didn't manage to see how.
>I also saw it feeding on some garbage this morning.
>
>Is this a common "accident" in birds ?
>How is the survival rate of such mutants ? "My" guy seems to be able to feed
>at the moment, but will that be the case in a few months ?

Birds are amazingly survivable. I've seen a variety of species with odd
bills, adult birds that presumably were able to feed themselves. I've had
Steller's Jays (twice) at my feeder with a broken-off upper mandible that
seemed to be surviving by shoveling seeds into their mouth, but I'll admit
they weren't around for a long time. We have a starling specimen in the
museum with a bill shaped and sized about like that of an Eskimo Curlew,
and it was trapped perfectly healthy as an adult. I too have seen at least
one hook-billed crow and can recall a few other cases of maxilla and
mandible not working together particularly well.

On the other hand, as a bird's bill is such an important element in its
feeding, it would seem that in most cases, drastic alterations to that
foraging implement would be deleterious if not quickly lethal.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416