This Bizarre Bat Has The Most Convoluted Face Of Any Bat Species, And A Very Unique Approach To Mating

When Professor Bernal Rodríguez-Herrera at the University of Costa Rica received a phone call about some ugly bats in San Ramon, Costa Rica, he didn’t think much of it. “Most people think all bats are ugly, so I didn't take the report very seriously at first,” he said. As it happened, what they had spotted were rarely observed “masked seducers”: the wrinkle-faced bat.

The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.

As something of a bald ape myself, I don’t like to call animals ugly, but it’s hard to argue that it’s not a fitting description for the wrinkle-faced bat (Centurio senex). With the most convoluted faces of any bat, it can be hard to work out what’s what when looking at them. Wrinkle-faced doesn’t really capture just how wrinkly they are.

However, that appearance is no accident. Oh no. Theirs is a wrinkled face born of millions of years of evolution that has molded them into juice-slurping specialists with a very unique lifestyle, something Rodríguez-Herrera got to discover when he made the good decision to follow through with that report of “ugly bats” and landed the jackpot.

“When they sent photos, we realized that these animals were wrinkle-faced bats, Centurio senex, an incredible find,” he said. “Not only is this a rare bat species that a lot of bat researchers would love to have on their life lists, these bats were doing something that no one had ever seen before.”

It was a surprise in itself to find them in a cloud forest in San Ramon. What the authors of the 2020 study saw when they tracked them down was that they were males, lots of them, all perching together on relatively low-hanging branches.

You know when you’re looking at a male wrinkle-faced bat because they pull out something that’s apparently very sexy to the female of the species: a face mask made of skin. Oh yeah.

When the researchers noticed that the males were all flocking together at around 6 pm and flapping off again at midnight, they realized that this was likely a kind of courting behavior – one that had never been reported before. Their rousing performances involved singing through the skin mask, and it’s thought that by singing through the flap of flesh, they can alter the acoustic properties of their singing.

The bats emit unique vocalizations consisting of only the fundamental frequency, without the harmonic overtones you get in other leaf-nosed bats. As well as identifying this unique way of flirting, the team also got to see what happens when it pays off, as they became the first to record two wrinkle-faced bats mating.

"A female obviously could not resist the seductive calls of one of the masked singers any longer," said Marco Tschapka, a research associate at the Smithsonian Tropical Research Institute from the University of Ulm, in a release. "She joined the perching male and quickly they dedicated themselves to their private business, thus confirming our idea that the males were there to attract females."

So, just remember that the next time you think something, or someone, is ugly. Perhaps they’re just perfect to the right partner.

And if interesting bats are your thing, why not check out the bumblebee bat?