What animal has three vaginas?

If you said kangaroo, you’d be right. And you’d probably have a job in the biology department. For the rest of us this one was news.  

It turns out that all marsupials have this three-vagina setup. And they have two uteruses.

So why does a lady kangaroo have a reproductive system like this?  

Well, the reason there are three vaginas is because they are designed totally differently to us. They have two tubes that carry urine from the kidneys to the bladder, that travel in spaces between each separate vagina. Ours go round the outside of just one.   

Two of these vaginas are used as channels for sperm, and the one in the middle is used for giving birth. But it only forms when the kangaroo is ready to give birth. Wild.  

This middle vagina is pretty narrow because of the urinary tract on either side, so the mother kangaroo only has a month-long pregnancy before giving birth to a very tiny baby through this middle vagina. When it’s born, it’s deaf, blind, and only the size of a jellybean, so it hangs out in the mother kangaroo’s pouch for another eight months or so before it hops out into the real world.  

What’s really cool about this reproductive system is that is can act like a tiny conveyor belt of kangaroo babies. While a joey is hanging about in the pouch, growing and getting ready to become a fully-fledged outdoor kangaroo, the mother can mate again and get pregnant, again. Then a second and even a third baby can grow in one of her two uteruses until the baby is a bundle of around 100 cells, and then it can just stop growing until she’s ready for it to get to birth size. It just waits for its sibling to leave the pouch, just like you would wait for a tenant to leave the flat you’re wanting to move into. When a pregnancy can be paused like this it’s called ‘embryonic diapause’.  

And side note – contrary to popular belief, male kangaroos do not have a two-pronged willy. 

I’m not sure about you, but I think that’s pretty cool. If you want to hear more amazing biological stuff from us, make sure to subscribe to our newsletter (at the bottom of the page) so we can keep taking you on new and ever more interesting Sex in Space journeys.