Why is a new feral male coming around even though there are no females in heat here?

My colony is pretty small. There's an adult pregnant female whose routine is currently messed up due to being trapped by me a couple of weeks ago. There's her two daughters (both spayed), and three 8 week old kittens. I've basically only seen one male around here, but he wanders far and wide. I suspect he is getting food somewhere else because I have only seen him eat here once. He's not neutered and I hope to trap him, but I'm not quite sure how to do it since he doesn't eat here nor does he show up on a schedule.

Lately I have seen another male coming around. He was just here and the spayed female was under my van with her three 8 week old kittens. He started to walk towards them and the momma went to the edge of the van and looked ready to fight if need be.

So my questions are:

Can the kittens possibly be in heat at 8 weeks old? Nothing I have read seems to indicate this possibility, but why would this other male be coming around?

If I do witness a fight between the any of the cats in my colony with this newcomer, do I intervene? If so, how?

Cats wander. Especially toms. He may be looking for a new territory or just passing through. I doubt he's interested in the kittens, and likely wouldn't fight the mama cat unless she started it. I suppose you could intervene if you see a fight, but cats mostly handle that kind of thing themselves so I don't think it's necessary.

 Welcome to TCS and congratulations on doing such a great job managing your ferals. If the tom is a young one, there is a good chance that he comes from a colony and was driven off by the senior tom cat and is just looking for a new hangout. with the kittens being so young, they are alot less threatening and if he is a young cat, they act amusing as well. I wish you great success in your TNR efforts! sincerely, Susan

A Tom will sometimes kill kittens to bring the mother into heat so he can breed her.  You might want to discourage/trap him, protect the kittens.  The mother might be in heat already,  the one we trapped in the backyard came into heat when her kittens were 7 weeks weeks old and still nursing.

It sounds like the mama cat is already spayed.

When toms kill kittens it's usually newborns. By 8 weeks they ought to be pretty safe from him. He might be scouting out the females, making plans to come back in a few months .

Thanks for all the replies. I really like this site because of the different perspectives everyone has to offer.

The newcomer looks older as he is rather large and seems to have quite a few scars. Maybe he was recently overthrown in his colony.

I was hoping to trap him this morning as I have a standing TNR appointment on Monday, but he didn't come around today.

I'm going to trap those kittens as soon as they are 3lbs, so hopefully they won't attract any other males.