In the UK there are about one million feral cats, in the USA abou 70 million. It is no good trapping neutering and releasing ( the trauma is probably worse than being hit by a plastic BB pellet). This wll not reduce the population of feral cats as there is always a population of cats waiting to move into a vacated territory. From my observations I would guess that most of the autumn born kittens die of starvation or get gobbled up by bigger predators during the winter. The feral tomcat that we feed does us the sevice of keeping away another tomcat that sh1ts everywhere. Feral cats are not pets that have strayed, they are wild animals just as much as rats and foxes. There are plenty of websites that deal with the subject, if you want to know more.