For the first time, a study published in Current Biology has documented sex without penetration in a mammal – specifically in the serotine bat. Researchers found that the male bats use their oversized penises to move the female’s tail sheath away and maintain contact mating, instead of functioning as a penetration organ.
The penises of bats are about seven times longer than the vaginas of their partners and have a head heart shaped seven times wider than the vaginal opening, making penetration impossible. Nicolas Fasel, from the University of Lausanne, Switzerland, and lead author of the study stated that this type of copulation had not been described in mammals until now.
Very little is known about how bats mate, and this study observed genitals during copulation using images from cameras placed behind a grate that they could climb onto. The researchers analyzed a total of 97 pairings from the Dutch church and the Ukrainian center. They also observed that the female’s abdomen appeared moist after copulation, suggesting the presence of semen, but more studies are needed to confirm that sperm was transferred.
The researchers characterized the morphology of the genitalia of serotine bats by measuring the erect penises of live specimens and performing necropsies on those that died. When erect, the penises of serotine bats are about seven times longer and seven times wider than the vaginas of females of the same species. The researchers plan to study