Birthing in natural environment

Question
I bought 2 baby rabbits at age of 7 weeks and got them vaccinanted, but not neutered/spayed as we were thrilled of idea of having a large family of bunnies. The idea was to let the rabbits breed couple of times and then have them and the babies neutered/spayed. we built a large cage with roof and 3 solid walls and tray bottom, which we align with sawdust and wood chips, with 2 rooms, space underneath the cage and outside run of 5mx5m. We lined the bottom of the run with chicken wire and put 50-70cm of eath on top of the wire. On top of this we used to take rabbits into the house and let them run free until they started spraying at which point we tought it was more pleasant to keep them outside. We still cuddle and handle them every day and take them for walks to our forest in leash. 2 weeks ago the rabbits started making tunnels into their run and it soon turned out to be a complete maze or tunnels with 7 entrances. Then 1 week ago the doe, now 4,5 months old started building nest into the tunnel. She used lots of hay and pulled of her fur and also some from the buck. She closed all the other entrances except 2 and started hissing the buck away when he was trying to get down the tunnel. Otherwise they seem as usually very loving and kind to each other. The question I have is, will the buck really try to kill the kits if he gets a chance to? Why would he do this, can he not smell that they are his own, like with some other animals? If I have to separate the buck, then when can I introduce him to the babies. I think the babies are live and well as I see the mother opening the entrance I assume is closest to nest about twice a day and going down there for 5-10mins, pushing out some stuff from the nest and then closing this entrance again. She also eats and drinks more than usual. Can I assume all is well without my interventions altough I can't check out the nest since it's underground or should I try to open it to check it out?

Answer
Dear Mira,

I assume you're in the U.K., since you mention having the bunnies vaccinated.  But if you are in the U.S., then note that there are not vaccines either necessary or approved for use in rabbits.

The male is not likely to harm the babies.  But the mother is very likely pregnant already again, since rabbits are induced ovulators.  Please read:

www.bio.miami.edu/hare/breeding.html

before you get more bunny than you bargained for.

I would not bother mama.  Just let Nature take its course, and I'm sure all will be fine.  But be sure to have everyone  spayed/neutered ASAP.  For a scary wakeup call about rabbit breeding, please read:

www.bio.miami.edu/hare/scary.html

Hope this helps.

Dana