As the only mammals that can fly, bats are the oddballs of the mammalian world. But serotine bats stand out for another, glaringly obvious reason — when erect, a male’s penis can swell to almost a quarter of its body length. How these bats use their humongous genitals to mate — without penetration — is a method never seen in a mammal before, researchers report in the Nov. 20 Current Biology.
Instead of inserting its penis into the vagina, a male uses it to move aside a membrane covering the female’s genitals and then presses the penis against the female’s vulva and holds it there, often for just under an hour. In one observation, the behavior lasted more than 12 hours.
Once the deed was done, the fur around the female’s vulva appeared wet, which Fasel and colleagues suspect is due to semen. Other scientists told Fasel the wet spots look similar to those in which they’ve found semen after mating in other bat species, he says. These observations suggest the serotine bats are mating without penetration, a common practice in birds but one never observed in a mammal before (SN: 1/16/09).
“I think it’s super interesting because it sort of brings up a different function for a penis” aside from penetration, says Patricia Brennan, an evolutionary biologist at Mount Holyoke College in South Hadley, Mass. “It doesn’t surprise me that this is a bat because bats have some of the craziest reproductive strategies in mammals,” such as females being able to store sperm for six months or males having spines on their penises.
2023-11-22 09:00:00
Original from www.sciencenews.org