Two indiscreet cameras – one installed in an animal rehabilitation center in Ukraine and another in a church in the Netherlands – have recorded the elusive garden bats in the middle of a sexual encounter. Some recordings that have perplexed ethologists as they have revealed behavior that until now had never been seen in mammals: They mate without penetrating the female, according to a study published this Monday in the magazine Current Biology.
It is common for mammals to practice penetrative sex, but scientists have discovered an exception in this species of bat called hortelano or serotino (Eptesicus serotine). According to the researchers, It is the first time that non-penetrative copulation has been documented in a mammal.
As you have seen in the videos, these animals they mate by contact, something similar to what in birds is called kissing or cloacal opposition (the male places himself on the female and transfers the sperm to her using the same duct he uses to excrete). In a similar way, male bats of this species use their penis – which is seven times longer than the female’s vagina – as a kind of extra arm to facilitate copulation, but not as an organ of penetration.
In addition to being seven times longer than their partners’ vaginas, their penises have a heart-shaped head that is seven times wider than the vaginal opening. Both their size and shape would therefore make penetration after erection impossible, and researchers have now documented that they are used to facilitate such contact mating.
“By chance, We had observed that these bats have disproportionately long penises and we always wondered ‘how do they work?‘. We thought that perhaps it happened like with the dog, whose penis swells after penetration, or that they simply could not insert it into the vagina, but this type of copulation had not been seen in mammals until now,” he explained in a statement from press Nicolas Fasel, lead author of the study and researcher at the University of Lausanne.