Stubby

About a month ago, we spotted an odd looking bird in our yard that had a short, round body. A day or two later we saw it begging from a Mockingbird and realized that it was a tailless Mockingbird. After seeing it often, we started calling "him" Stubby.  We usually see him several times a day, making the rounds through our yards and up to the surrounding roofs.  We don't know how he lost his tail.  Was he born without it, or did he lose it during a narrow escape?  He seems to be doing well, maybe flying a little slower and less gracefully than the other Mockingbirds we see.