Rabbits image via Shutterstock

Pope Francis is in the news for saying Catholics don't have to breed "like rabbits." How prolific are rabbits anyway? Is there any truth to the phrase "breed like rabbits"?

Sort of. When a doe lets a buck know that she's ready to mate, he circles her, shows off his tail, and sometimes urinates on her. This is what passes for foreplay. Then, the act itself lasts about 20-40 seconds.

The real wow factor of rabbit reproduction is how fast they get around to breeding, and how often they can do it. The average rabbit reaches sexual maturity at 3-8 months old, and they have the rest of their 9-to-12+ years to get it on (though egg/sperm production drops off at around 3 years). Their breeding season lasts three-quarters of the year, and the does don't have an estrous or "heat" cycle. They're more or less ready to mate all the time. They don't have a menstrual cycle, either, so there's no special window during which pregnancy can happen. Does are actually induced ovulators, which means that intercourse stimulates ovulation. After 40 seconds of magic, the egg is emitted for fertilization.

Rabbits gestate for only 30 days, and usually have litters of between 4 and 12 babies (kits), depending on the breed. Once the babies are born, the doe can mate and get pregnant again as soon as the following day. If they maintain a pace like that and all the kits survive, the large-litter breeds are looking at about 100 babies per season. Stretch that out over a lifetime, and you've got over 1,000 babies per rabbit.

This Big Question originally appeared in 2012.