I would phone the RSPCA. If they wont help then any local animal rescues should be able to help you. I rescued a bird from one of my cats a few years ago. They came and took the bird to a bird sanctuary they have got at Crewe. It did not look to be injured. Just shocked. The bloke who came said he was quit e confident that it would survive. Thank goodness. I love my cats but they do have their down side. I do everything I can to prevent them from catching birds. They have not caught a bird since we moved here 6 years ago. Though they have had the odd frog.