Ravens

[George Hogg]

Watched a male in nesting territory flying with permanently open bill.
Is this due to an extra full crop(the male carries food to the incubating female in his throat pouch)or is it part of display,or just common behaviour?
..........George

[Amoeba]

There was a juvenile gull near by once who was grounded, couldn't fly. It had its beak permanently open and seemed lethargic, but managed to fly off eventually after some serious effort. Its windpipe was sticking out slightly from its mouth and it couldn't make a noise even though it tried.

I later read up about a bird disease, can't remember the name, that causes such symptoms and it can infect other birds, not just gulls. The sticking out windpipe had to do with swelling.

A classic symptom, so it said, was the birds keeping their beaks open and appearing unable to close them.

I know it's unlikely but it just reminded me of this. Maybe there are other symptoms you could look out for to rule it out.