Do you understand what a feral cat is Katy?

Feral cats are born in the wild.  They are not domestic cats.  I have never heard of anyone else that has spent so much money having feral cats sterilised to try to help fix the problem and to help to conserve the wildlife.  

As for your little bird, good for you lionrose I hope it recovers but usually they don't because of bacteria from the cats teeth. Been there done that with a young dove which survived for a few days and seemed well at first.  Apparently doves are deaf too (at least so I am told) so they don't hear anything coming.