I don't think feral male cats have much to do with their offspring. I do know that if they move in on another male cat and defeat him, they will kill all the kittens so they can start their own family. Kind of like lions do. All the young of the other male are killed.
I used to live near a guy who had a lot of feral cats around his place. If they came down to my property my dogs would kill them, but periodically coyotes would wipe out most of them, and they'd start accumulating again. As the population got larger and larger, you'd start to see crooked tails, short tails, or no tails, Iguess from all the inbreeding. Then the coyotes would wipe them out. Sort of a natural cycle I guess.
vickie