As the one mammals that may fly, bats are the oddballs of the mammalian international. However serotine bats stand out for every other, obviously evident reason why — when erect, a male’s penis can swell to nearly 1 / 4 of its physique duration. How those bats use their humongous genitals to mate — with out penetration — is a technique by no means noticed in a mammal earlier than, researchers file within the Nov. 20 Present Biology.
At greater than 16 millimeters when erect, the penis of male serotine bats (Eptesicus serotinus) has no probability of becoming within the feminine’s roughly 2-millimeter-long vagina, a discrepancy that triggered biologist Nicolas Fasel to surprise how those bats cross about getting it on. Movies accumulated on the Ukrainian Bat Rehabilitation Middle in Kharkiv from 2018 to 2021 and the attic of St. Matthias Church in Castenray, Netherlands, from 2016 to 2022 published the solution. With pictures, taken from beneath the bats, “shall we see in reality what used to be going down,” says Fasel of the College of Lausanne in Switzerland.
As a substitute of placing its penis into the vagina, a male makes use of it to transport apart a membrane masking the feminine’s genitals after which presses the penis towards the feminine’s vulva and holds it there, frequently for slightly below an hour. In a single remark, the conduct lasted greater than 12 hours.
As soon as the deed used to be carried out, the fur across the feminine’s vulva seemed rainy, which Fasel and associates suspect is because of semen. Different scientists advised Fasel the rainy spots glance very similar to the ones by which they’ve discovered semen after mating in different bat species, he says. Those observations counsel the serotine bats are mating with out penetration, a not unusual apply in birds however one by no means noticed in a mammal earlier than (SN: 1/16/09).
“I believe it’s tremendous attention-grabbing as it kind of brings up a special serve as for a penis” except for penetration, says Patricia Brennan, an evolutionary biologist at Mount Holyoke Faculty in South Hadley, Mass. “It doesn’t marvel me that this can be a bat as a result of bats have probably the most craziest reproductive methods in mammals,” corresponding to ladies having the ability to retailer sperm for 6 months or men having spines on their penises.
Fasel consents. Amongst mammals, bats “simply need to be the weirdos of the gang.”