Thank you both for your concern. I took him to the vet, his wing was also injured, (probably from flapping around in the cage), and his tail was out of joint. I chose to euthanize him, I don't think his quality of life would have been very good. He was the only bird in that cage at the time, so I am not going to use that cage again. He had been outside for 5 years without incident, butI guess it was not as secure as I thought it was. I am bummed, and I feel bad for him that this happened. I was not as attached to this one as I am to my other doves, though. Going to double check the other cage, though there isn't a way to get hold of them from outside, as it seems happened to this bird.