Here in Az ferrel cats are destroying the native bird population. It is an arid climate and the birds have always been on the razors edge of survival. Now that so many people have moved in, bringing their cats, the birds are declining at an alarming rate. San Pedro valley used to have the highest diversity of birds in all of America and now we are in serious danger of losing that diversity thanks to Fluffy and Tinkles. I think that if cats aren't kept in your house, they should be fair game like any other nuisance. I think our first responsibility is to native species, not irresponsible cat owners.