According to the Pet Food Institute, there are at least 65.8 million pet cats in the United States, and about half of them are outdoor cats. Add to that the millions of strays and feral cats, and there is certainly a sizable population of free-ranging cats in our country. Responses from professional rehabbers around the country ranged from 14 to 30 percent. If each outdoor cat only killed one bird per year, it would equal close to 40 million birds annually. The American Bird Conservancy has launched a national campaign to educate cat owners and encourage them to keep their cats indoors.
Some pet owners are quite resistant to keeping their cats indoors.
Cats hunt for the sake of hunting. Yes, but house cats are not natural in the environment. They have been introduced in vast numbers and at high densities. Opening the back door to allow kitty out to do what's natural for her disrupts the delicate balance with potentially disastrous effects on wildlife and the entire ecosystem. She needs fresh air and exercise.