I’ve just noticed a Robin in my garden with what looks like cotton around it’s beak! I don’t know what to do. It’s really upset me. It’s literally from half way down the beak to it’s face. I believe it’s thread of some sort as it’s colourful.
I'm not the best person to advise you, so hopefully someone with more info may be able to help.
It can be difficult to get close enough to a robin, or any bird for that matter, are you sure its cotton and not an insect with long thin legs, like a spider?
Mike
Flickr: Peak Rambler