There used to be a hook-billed magpie in my neighborhood, quite fat and
sleek looking, whose upper mandible extended beyond the lower by at least an
inch, and curved down. Reminded me of a riflebird. I was seeing it off and
on for almost a year, so I don't think the bill was a big impediment,
although once the upper mandible grows *too* long, it could break off, maybe
rather far back, and challenge the bird to learn a completely different way
of foraging.

I think this problem usually starts with the tip of the lower mandible being
broken off, allowing the upper to curve downward. Of the rehab birds we've
had with incorrectly growing beaks (that I can remember), several have been
Steller's Jays, but it can happen to eagles or anything. The corvids are
probably more able to adapt and survive and be sighted.

"Sighted" There's a good word for you Serge, to go with "boned," although
not really parallel.

Chris Maack
Bird Treatment & Learning Center
Anchorage, AK
btlc at name1.ak.net