As soon as orangutans go through puberty, they are pretty much expected to find a mate and start making babies. But as sexually frustrated high schoolers the world over will tell you, that's easier said than done.
The orangutans on Sumatra - and only those on Sumatra, so don't go blabbing to their Borneo cousins - have come up with a truly novel solution to make themselves as good-looking as possible coming out of puberty. They delay puberty, meaning they don't develop the secondary sexual characteristics like cheek flanges that pretty much say to all the female orangutans, "Yup, I'm here to get busy."
Some orangutans manage to delay the onset of puberty by more than ten years. And while that effectively means they remain children for an extra ten years, they are still able to do plenty of growing up. They spend all that extra time building up the strength necessary to overthrow the dominant males of their society when they finally do complete puberty. Exactly how the Sumatran orangutans are able to selectively arrest their development is still an open question, but it certainly seems they are the only male primates who know this particular trick.
Researcher Gauri Pradhan of the University of South Florida and her colleagues have described this effect in The American Journal of Anthropology. They point to the unique structure of Sumatran orangutan society, in which one male can monopolize the attention of all surrounding females for weeks at a time, as a reason why this delayed puberty evolved. They found that those orangutans who had matured later were significantly more successful than their counterparts in gaining sole access to the females.
While the idea of going straight from a biological child to controller of one's own harem may sound a bit bizarre - and indeed, applied to humans, seems like a rather fascinating if mildly disturbing premise for a sci-fi short story - it turns out to be the best evolutionary strategy for the Sumatran orangutans. But it does have some decided drawbacks, as the males get to enjoy their adulthood for even less time than you'd think. According to the researchers, such delayed puberty is strongly linked with early deaths among the briefly adult males.