The Science of Bats and Balls

A study by Dr. Scot Pitnick of Syracruse University has revealed that bats with bigger brains have smaller testicles than bats with small brains.

Isn't science fascinating?

Depending on any of the 300+ species of bats, testicle size in relation to total body weight varies. Testicles can comprise of .12% of body weight, up to a whopping 8.4% of body mass (yellow winged bat). How much wing power is needed to lug those cohones around? Ouch. In comparison, primate testicles only make up between .02% - .75% of total body mass.

Aren't you glad you're reading my blog today?

Here's what Dr. Pitnick (pictured left) and the others found: Bat species where the females were promiscuous, the males had evolved larger testes but had small brains. In species where the females were monogamous, the situation was reversed. Isn't that interesting? The bigger the nuggets, the smaller the noggins.

So why is this true?

Brain tissue and sexual organs require a lot of metabolic energy to produce and maintain. The different species appear to have evolved a preference for developing one organ more than the other, depending on which will help them produce more offspring. This does make sense. If the female is promiscuous, male bats will have to produce more sperm in order to compete with other male bats. It's one big competition to fertilize the female's egg. “And this may be especially true in some species of bats where the females store sperm for several months,” reports Dr. Pitnick.

So what about the monogamous bats? Pitnick and his colleagues had erroneously predicted that in a species with promiscuous females, males would require bigger brains in order avoid being cuckolded. They were surprised to find the opposite was true. Does having a bigger brain help the monogamous bat produce more offspring with his female companion? Maybe.

Perhaps being faithful just takes more brainpower.

This study is bad news for perhaps the smartest bat in the entire universe...

Holy tiny testicles, Batman!