For tips about find out how to flirt whereas sporting a masks, take notes from nature’s consultants: male wrinkle-faced bats. The primary video of a wrinkle-faced sexual encounter exhibits a male overlaying his face with a masklike flap of pores and skin whereas wooing after which, at a strategic second, dropping the masks.
Even the fundamentals of how bats mate — whether or not a male stakes out territory and advertises, or females simply store amongst a crowd of show-offs — stay a thriller in additional than 90 p.c of the world’s 1,400 bat species, says mammologist Bernal Rodríguez-Herrera of the College of Costa Rica in San José. So it was a stroke of luck when a tip from nature guides in 2018 led him to the primary scientific observations of courtship in one of many extra elusive bats within the Western hemisphere’s tropics, the wrinkle-faced bat, Centurio senex.
Males, however not females, develop free folds of largely white fur under the chin that appear to be a pulled-down neck gaiter. A male can use his skinny thumbs to tug the fur flap up over his chin and mouth.
For the primary time, researchers have videoed the mysterious masked mate-courting of a male wrinkle-faced bat (Centurio senex). Together with his pure white furry face masks within the cover-up place, a male dangles in a Costa Rican rainforest, calling ultrasonically for feminine consideration. When a feminine swoops in, he drops his masks earlier than they mate, then makes use of his skinny thumbs to tug the fur flap up over his chin and mouth as soon as the feminine has moved on. Nonetheless a puzzle: What’s it in regards to the masks that helps a male woo?
It doesn’t appear doubtless that solely males would want covers for cold chins. Single-sex excesses usually are for showing off, like peacock feathers fanned out in competitors for feminine favor (SN: 6/16/15). Now a lucky first look at wrinkle-faced courtship means that the masks one way or the other play right into a wooing competitors, Rodríguez-Herrera and colleagues report November 11 in PLOS ONE.
For weeks, researchers watched male bats convene within the forest from about 6 p.m. till midnight, hanging the wrong way up specifically spots with their masks on. Different bats sometimes flapped shut briefly, however researchers couldn’t inform why.
The dangling males, it turned out, have been singing. Human listening to picks up a lot of tropical night time sounds, such because the calls of frogs and owls, however not bats. Bat-recording devices, nevertheless, revealed an amazing roaring ultrasonic bat songs. The sounds dipped into the vary of human listening to solely when a flyby customer made a fast intrusion. The males additionally “transfer the guidelines of the wings, always,” he says. He can’t inform if the wing rustling contributes any sound, however “we predict it’s a part of the courtship show.”
Seeing males collect in a particular place to sing suggests to Rodríguez-Herrera that the wrinkle-nosed species takes a singles bar strategy to mating, to this point hardly ever reported amongst bats. Extra scientifically often known as lekking, males cluster and show whereas females store for a contributor of genes to the following era. Assist elevating the ensuing offspring shouldn’t be on supply.
For weeks, these male bats in Costa Rica spent evenings rubbing wings and singing the wrong way up. The pale masks may work as a visible lure in dim mild or may play a task in wafting scents, a romantic function in another bats’ courtships. Or perhaps the flap “helps sound resonance,” Rodríguez-Herrera muses. “We have no idea.”
What the researchers lastly noticed was one wrinkle-nosed mating. A feminine landed on a male’s perch. The 2 confronted one another briefly. And as he repositioned himself for intimate contact, his masks went down.