Mammals typically mate through penetrative sex. However, a study by researchers at the University of Lausanne (Switzerland) shows that the broad-winged bat (Eptesicus serotinus) mates without penetration. The results of the work are published today in the journal Current Biology.
The authors emphasize that it is For the first time, non-penetrative sex has been documented in a mammal. “The penis of these bats is about seven times longer than the female vagina and the heart-shaped head is seven times wider than the vaginal opening,” the researchers describe.
Nicolas Fasela researcher at the Swiss University and lead author of the study, points out that “both the size and shape of the member of this species of bat would make penetration after erection impossible.” So instead of functioning as a penetrating organ, this is Eptesicus serotinus “He uses his oversized penis as an extra arm to push the female’s tail sheath to the side so he can maintain contact mating.”
This behavior, he adds, “Resembles the ‘cloacal kiss’ of birdsin which the male placed on the female transfers the sperm via the cloacal duct, the same duct used for excretion.”
In the study, researchers were able to observe these bats’ genitals during copulation Cameras placed behind a grid that these animals could climb onto.
Citizen Science
Fasel worked with a Ukrainian Bat Rehabilitation Center who occasionally filmed mating pairs, along with a bat enthusiast and citizen scientist named Jan Jeucker, who spent hours filming the flight of broad-winged bats in the attic of a church in the Netherlands. In total, the team analyzed 97 pairings: 93 from the Dutch church and four from the Ukrainian bat rehabilitation center.
The Video recordings revealed that bats do not practice penetrative sex. The researchers did not observe penetration at any time during the recorded copulations and found that the erectile tissue of the penis enlarged before coming into contact with the vulva.
During mating, male bats grabbed their partners by the neck and moved their pelvises (and fully erect penises) in a trial-and-error manner until they came into contact with the female’s vulva. At this time, they remained silent and hugged each other. to the females.
On average, these interactions lasted less than 53 minutes, but the longest lasted 12.7 hours. After copulation, the researchers noticed that the female bats’ abdomens appeared moist, indicating the presence of sperm. However, more research is needed to confirm that sperm was transferred in these alleged matings.
Genital morphology
The team also characterized the morphology of the genitals E.serotinus Measuring the erect penises of live bats captured as part of other studies (bats and other bats are known to have erections under anesthesia) and performing necropsies on dead bats in rehabilitation centers.
Measurements showed that when erect, the penis of broad-winged bats is about seven times longer and seven times wider than the female’s vagina and is about a fifth the length of the head of her body. In addition, they have unusually long cervixes, which could help females select and store sperm.
Researchers speculate that this species of bat evolved large penises to remove the webs from females’ tails and thereby avoid sexual relations.
“These bats use their tail membranes to fly and catch insects, and the females use them for this too Cover your lower parts and protect yourself from men“But the males can then use their huge limbs to overcome the tail membrane and reach the vulva,” says Fasel.
The team plans to study the mating behavior of broad-winged bats in more natural contexts. They also study the penis morphology and mating behavior of other bat species. “We’re trying to develop one “Porn Shack” for bats“It will be like an aquarium with cameras everywhere,” jokes the researcher.
reference:
Fasel et al. “Mating without intromission in a bat, a novel copulation pattern in mammals” Current Biology (2023)
