if you separate a bonded pair... its not good for them and there is no proof they'll be good with a new rabbit. If you are looking to bond, get a neutered rabbit opposite gender of yours.
did you go into robbie's cage unannounced? Might be territorial stuff... and he's saying STAY OUT. Robbie MIGHT be a girl and not a boy. If Robbie's building a nest... expect kits within the week unless it's a false pregnancy.
sometimes, if kits get dragged out of the nestbox (hanging on to mom's teats) they get cold. Sometimes mom wants to clean up to prevent predation of the other kits. SOMETIMES she doesn't wait for the kits to be completely dead to start the clean-up process. If she's a first-time mom, she...
she could simply be some "oddball" colour from poor breeding.
She doesn't look like a blue otter to me. Does she have a triangle of brown behind her head.
She looks more like an opal.
that's 16 inches deep! That's as long as what a large breed rabbit uses. Seriously... they only need it to be 10 inches long. sit your holland lop in a box, add one inch all around. long boxes encourage does to foul the box OR sit in the box and smother them.
1. let rabbit do her job. don't intervene unless necessary. Sometimes takes three days for milk to come in. Babies can survive that long.
2. don't be afraid to foster from one rabbit to another.
3. save fur from any failed litters to give other does who don't pull enough.
4. give the...
size wise probably about 8-10 weeks.
Sometimes it's hard to know why bunnies die, particularly when it's completely unexpected. As prey animals, sometimes they just die and we don't know why.