As much as you might like cats, you can’t ignore the fact that outdoor cats kill birds. Of course, nobody cares when outdoor cats kill mice, but killing birds is usually a no-no since many people like birds.
So to protect birds, many people are proposing a variety of methods ranging from cat curfews to fences to keep cats out of certain areas to make safe havens for birds. There’s no doubt that cats will continue killing and eating birds, but birds need to live too. Perhaps one solution is to force more people to own mice. That way the cats would spend more time killing the mice and leaving the birds alone, but then people might get upset at so many rodents being killed and we’d be back where we started from.