The problem with feral cats is that people feed them. People who would never think about feeding racoons will feed cats right off the back porch. A well fed cat can have two litters a year. So you can go from 1 cat to 60 cats in two years, as long as you keep putting out the food.
About the time you have a back deck completely covered with cats, you realize that half of them are starving or diseased or all beat to Hell, and all of a sudden you realize that maybe this wasn't the smartest thing in the World to do...
I think you have to start with 2 cats.
Good point!
Don't feed the cats, feed the GATORS!
THe right and humane thing to do is to get those 'feral' --'homeless' cats fixed...like us kind people do. THen yu just feed them. Let them have a semi-decent life. You won't have rats....and they will leave the birds alone if they have food.