I have a question?
(Redmond, Oregon, United States)
What if you find 1 alive kit and 3 dead kits ... will the doe feed the live baby?
Sorry about the dead bunnies.
Our guess is 'probably.' Depending on why most of the babies were dead. We'd hope 'yes,' and give her the chance to look after the living kit. Don't forget -- she only spends a few minutes per day in the nest, so don't assume she's not caring for the kit if you never see her in the nest. In the AM, check the bunny's tummy. If it is round and full, all is well.
The next biggest concern will be keeping it warm, since it has no one to cuddle with. Try pulling (or brushing) extra fur from the doe to cover the little guy. (Sometimes the doe realizes the need and does it herself.)
Good luck, and God bless you,