Pensioner reveals the secret of the broad-winged bat's penis
Normally, mammals produce their offspring through penetrative sexual intercourse. But the penis of the broad-winged bat is far too large for the female's vagina. So how do the little animals mate? A pensioner has now provided some surprising answers.
The oversized penis of the broad-winged bat has long puzzled researchers: When erect, it is seven times larger than the vagina of the female bat. In addition, the heart-shaped thickened tip is far too thick for the vaginal opening, which is only around 1.1 millimetres in size. Normally, mammals produce their offspring through penetrative sexual intercourse. But given the size of the penis, it seems impossible for the male broad-winged bat to penetrate his partner. So how do the animals mate anyway?
The answer is provided by a Dutch pensioner. Jan Jeucken filmed a group of broad-winged bats in the attic of his village church for many months. He sent the footage to biologist Nicolas Fasel and his team from the University of Lausanne in Switzerland. The researchers were thus able to observe for the first time that the male bats use their penis as an additional arm to enable mating through mere contact of the genitals, as they write in the journal "Current Biology".
The special thing about the images: The scientists were able to see the genitals of the two bats during the act for the first time. This was made possible by a grid on which the animals were having sex. The sex act lasted between 53 minutes and 12.7 hours.
First copulation through mere contact
Further real-time observations of almost 100 pairs of bats during mating confirmed that the males did not "use their penis as an intromittent organ", explained the scientists involved in the research, Susanne Holtze from the Leibniz Institute for Zoo and Wildlife Research and Marcus Fritze from the University of Greifswald.
Instead, the male "mounted" the female on her back, as many other mammals do, and used his long penis like an arm to bypass the flight skin, which the female uses to protect her genital tract. This was followed by a long motionless embrace, also known as "contact mating". "After copulation, the fur on the female's abdomen appeared wet, indicating the presence of ejaculate and sperm," the biologists say.
Although this form of reproduction is common in birds, it has not yet been observed in a mammal. This means that broad-winged bats could be the first known mammal species for which mating without penetration has been documented. "Assuming that sperm were actually transferred during these matings, our study reveals a completely new copulation pattern for mammals," Fasel and his team state. Whether this form of non-penetrative mating also exists in other bat species still needs to be investigated.
In their own words, the research team has bat enthusiast Jeucken to thank for the discovery. Because of his passion, he is "the best person" to understand bats, says Fasel. Although the pensioner has no scientific background, he is named as a co-author in the study.
Source: www.ntv.de
