TIL: Why Do These Monkeys Have Big, Colorful Butts? | Today I Learned

[Music] So female mandrills, they do actually like males with nice big colorful bumps. The males, they are so handsome; they have both pink, purple, blue, and red, and it shines so brightly that you have no doubt where he is when he walks in the forest far away from you.

[Music] Like other monkeys and apes, they live in a hierarchy. So, if you look into a troop of mandrills, there will always be one mandrill more colorful than all the other males, and that will be the high-ranking male. The lower-ranking males will also have colors, but they will be less splashy.

Actually, the males, they actually fight for the level in the little monkey society. So when a lower-ranking mandril is fighting his way up through the ranks, when they win the crown, if you can say that, his testosterone will actually rise, and the colorful face and bum will actually come by.

[Music] Itself, so the high level of testosterone actually leads them to lose hair on their bums, so the bright skin is displayed even more. The advantages of being big and colorful is that you get the right to meet with the [Music] females.

It does show which male will give her the good kits. So, it's the ability to actually color increase or color enhance that tells all the females that, "Wow, you ladies, come, come to me because I can give you your good offspring." Look at the P!

Okay, ah, that's nice; it's just a pink behind shining in the jungle. [Music]