A few years ago, biologist Nicolas Fazel of the University of Lausanne in Switzerland and his colleagues became interested in the penises of serotinous bats, a species found in the forests and attics of old buildings in Europe and Asia.
Serotine bats have unusually long penises with wide, heart-shaped heads. When erect, this member is about seven times longer than the woman’s vagina, and its bulbous head is seven times wider than the woman’s vaginal opening.
“We wondered how it worked. How could it be used for mating?” Dr. Fazel recalled.
What they discovered overturned an assumption about mammalian reproduction: that reproduction always requires penetration.
in studyIn a paper published Monday in the journal Current Biology, Dr. Fassel and his colleagues present evidence that serotinous bats mate without penetration and are the first mammals known to do so. announced. Scientists have discovered that male bats do not use their penises to penetrate their partners, but instead use their penises to push their partners’ caudal membranes out of the way, lining up the openings and allowing them to engage in contact mating. discovered. This behavior is similar to that seen in birds and animals. It’s known as the “cloacal kiss.”
To learn how these bats overcome the large differences in genital size, Dr. Fassel and his colleagues analyzed about 100 videos of mating serotine bats. The video was provided by a bat rehabilitation center in Ukraine and a citizen scientist filming bats in the attic of a church in the Netherlands. The footage revealed a mating strategy unlike any other used by mammals.
While the two bats hang upside down, the male climbs onto the female’s back and grabs her by the scruff of the neck. With a firm grip, the male uses his erect penis to push the female’s caudal membrane to the side and probe between her legs until he finds the location of her female vulva. The man then presses the heart-shaped head of his penis against the woman’s vulva and holds it there until she completes the act. For most of the couples the researchers observed, the process took less than an hour, but for some it lasted nearly 13 hours.
“This is a really weird reproductive strategy, but bats are weird and they have a lot of weird reproductive strategies,” said M.M., who studies the evolution of genital morphology but was not involved in the study.・Patty Brennan, a biologist at Holyoke College, said: She said bats have evolved penises with everything from hairs to spines, so she wasn’t surprised that some species ended up with penises too large to penetrate their partners. Pointed out.
The serotinous bat’s spade-shaped penis may not be well-suited for penetrative sex, but its size and shape make it the perfect tool for moving the female’s caudal membrane. This flap that connects the bat’s tail and legs not only aids in flight, but also serves as a means of covering the female’s vulva, making it difficult for potential mates to access it.
Fasel and his colleagues found that males of serotinous bats evolved disproportionately large penises to bypass females’ caudal membranes, as part of a “really interesting evolutionary arms race based on social and sexual conflict.” Dr. Facel said he suspected that.
Like the males of their species, female serotine bats have unique reproductive organs. Their cervixes are unusually long, presumably to help select and store sperm.
Dr Fassel and his colleagues plan to study the mating habits of serotinous bats in more detail, as well as other bat species. He said he wouldn’t be surprised to find contact mating in other bat species or other mammals. “I have some doubts, but I’ll keep an open mind,” he said.
Dr. Brennan said, “I think there are probably quite a few strange forms and behaviors that we don’t know anything about.” For too long, she says, such research “wasn’t considered serious academic research.” She argues that the paper’s findings prove that even the most scandalous fields of science have value.