The biology of a female kangaroo is just out of this world. Mating even doesn’t begin to explain it. For starters, female kangaroos have three vaginas (tripartite vaginal canal) that all meet at the opening. Each has side tubes that take the sperm up the central tube for the baby kangaroo to come out.
What you mostly know about the kangaroo is its enviable natural pouch. This one is not just for carrying the baby in. it serves as an additional outer uterus, to compliment the two interior uteruses. When the female (doe) is ready for sex, she emits a scent that will be caught by the males (bucks). Since they live in groups called, guess the name?-mobs-they have no trouble finding a male who’s ready to give it a go. He follows her around, as he strokes her tail and smells her urine, which all serve as foreplay before they get into the main dance. The actual mating is pretty lengthy and goes on for 10-15 minutes.
After the sperm fertilizes the egg, the embryo will develop for about 33 days, come out-blind and hairless-before its put into the cozy pouch. It will nurse there on one of the mother’s four nipples and the mother goes to mate again. The mother will determine whether she wants the embryo to develop or not, even keeping it there until she needs it.
After the first joey is ready to go out of the pouch, its sibling comes out and goes into the pouch for development. The doe can decide if she wants to mate again or she’s had enough. Kangaroos can have three joeys at any one time. And guess what else? She can produce different milk for each of joey, based on how many calories he/she needs. As of that’s not all, the female can even determine the sex of the babies!