Scientists have observed that European bats adopt a unique breeding strategy that challenges conventional understanding of mammalian mating behavior. This research, conducted in the attic of a church in the Netherlands and at a bat rehabilitation center in Ukraine, reveals non-penetrative reproductive sex in bats, a previously undocumented phenomenon in mammals.
Unique mating behavior revealed
Researchers have recorded the first known cases of non-penetrative reproductive sex in mammals. This observation was made in the broad-legged bat (Eptesicus serotinus), a species found in the attic of a church in the Netherlands and in a bat rehabilitation center in Ukraine. In mammals, including humans and bats, fertilization usually occurs inside the female, with males using their penis to release sperm near the eggs during mating. This discovery therefore represents a significant departure from the norm.
The unusual reproductive anatomy of the broad-winged bat
The study, initiated by Nicolas Fasel, an evolutionary biologist at the University of Lausanne in Switzerland, began by observing the broad-winged bat’s unusually large penis, which accounts for 22 percent of its head-to-body length and has a bulbous, heart-shaped tip. This anatomical feature has raised questions about its functionality in traditional mating processes.
Credits: Current Biology
Observations of mating behavior
Jan Jeucken, a bat enthusiast, provided crucial video evidence of bat mating behavior, captured from a vantage point in the church attic. The footage shows males grabbing females from behind and moving their erect penises around the females’ cock membranes in search of the vulva. Despite the lack of penetration, sperm are believed to successfully enter the vagina, as evidenced by the wet fur on females’ bellies after mating. This mating method, which lasts less than one to more than 12 hours, represents a significant departure from the typical reproductive strategy of mammals.
Implications and future research
Although the scientists did not sample the females’ fur to confirm sperm transfer, the evidence strongly suggests that their interpretation of the behavior is correct. This discovery opens new avenues for understanding mammalian reproduction and evolution and highlights the diversity and adaptability of reproductive strategies in nature
This remarkable discovery about European bats confronts us with the extraordinary diversity of nature and reminds us that there is still so much to be discovered about the mysteries of animal life. Beyond a simple biological curiosity, this observation sheds light on our understanding of mammalian reproduction and opens new doors to exploring the countless mysteries still hidden in the natural world. Bats, with their atypical mode of reproduction, become messengers of a wild world in which the exception is the rule, inviting science to continue its journey into the unexplored depths of evolution.