It looks like a beak injury--those arerelatively common among chickens; theyjust happen to rub themselves against wire, rocks, plastic, etc.I have an Easter Egger that once had a a really large lesion like that on her beak that lasted for at least a month (apparently, it takes a while for injuries like that to heal). But after a while, layers of the beak grew over the wound and she was fine again. And just recently, one of my White Wyandotte Bantam hens got a scratch on her beak that turned into a lump with a scab. That lasted a week before it finally healed. With both birds, I never found out how they injured their beak, but they were fine. As long as the injury to your bird's beak doesn't seem to get any worse (if it does, I'd isolate the bird in a hazard-free area), the beak should heal in time. If you want, you could put some antibiotic ointment (nothing that contains caine/cain ingredients, as those are harmful to chickens) on the wound, just to be safe.
