Most people can't tell my dogs apart but it would seem the garden birds can. I only have one bird chaser and if he goes out they fly straight off but if the others go out they just continue feeding. So I am wondering if they can tell one Elkhound from another when most people can't.

I don't know much about birds' sense of smell but their eyesight allegedly is incredible, so perhaps they can spot tiny subtle differences between your dogs - not just appearance but maybe little mannerisms.

my ducks could tell the difference between our dog and a friends viisting one.  visiting dog was also used to poultry and ignored but my poor ducks had total hysterics and fled!

> so perhaps they can spot tiny subtle differences between your dogs - not just appearance but maybe little mannerisms.

I think they must be able to tell predatory mannerisms/behaviour.
I've been quite amused at a crow we've been spotting on our walks. It will stay where it is untill we are about 10ft away from it, then it casually flies behaind us, out of the way. Buster shows an interest in the bird, but he's not a chaser and I am sure the bird can tell that Buster is no threat to it.

Birds that visit the garden seem to tell when the cat is showing more than a passing interest in them too.