I suppose a nest of days old kittens if found by a fox would be considered fair game and a goodly sized meal, but only if there was no mother cat around to see it off.

Driving home late one night (or should that be early one morning) I slowed to avoid a full sized fox that came bolting out of a garden, closely followed by a cat about half its size. Judging by the speed of the fox and the ferocity of the cat, I'd say the fox was losing big time.

Your fox may be eating tiny kittens hence no feral cats, he may be eating all their prey (although if there are enough rabbits, there's not much need for a fox to eat mice, rabbits are a better sized meal and not so hard to catch), or it may just be that your neighbour up the road has come to his senses and neutered the tomcats.

LTS