Serotonin bats use penises in a bizarre way during sex, scientists say Science and technology news
Scientists have found that a species of bat uses its penis in a unique way during reproduction, avoiding complete penetration.
Researchers from the University of Lausanne i Switzerland studied the serotonin bat, which has a penis about seven times longer than its partner’s vagina.
That animals also has a heart-shaped head that is seven times wider than the vaginal opening. The size and shape in theory make penetration impossible.
But the researchers say the bats use their oversized penis as an extra arm to push the female’s tail sheath out of the way.
The unique use of the appendage allows the bats to engage in contact mating – a behavior more commonly seen in how birds reproduce.
First author Nicolas Fasel said: “By chance, we had observed that these bats have disproportionately long penises, and we always wondered, ‘How does that work?’
“We thought maybe it’s like in the dog where the penis swells in after penetration so they’re locked together, or alternatively they just couldn’t put it inside, but that type of copulation hasn’t been reported in mammals until now.”
The researchers observed the unique mating ritual with cameras placed behind a grid the bats could climb on.
Their studies found it during mating. The male bats grabbed their partners by the neck and moved their pelvises in a probing manner until they made contact with the female.
At this point they remained silent and held the females in a long embrace. These lasted about 53 minutes on average, with the longest incident stretching to 12.7 hours.
After mating, the researchers observed that the bats’ abdomens appeared wet, indicating the presence of sperm. Further research is needed to confirm that sperm were transferred during events.
The researchers suggested that the male bat may have evolved their oversized penis to push aside the bat’s tail membranes, which the females can use to avoid sex.
Professor Fasel suggested: “Bats use their tail membranes for flight and to catch the insects, and female bats also use them to cover their nether parts and protect themselves from the males, but the males can then use these large penises to overcome the tail membrane and reach the vulva .”
The researchers collaborated with a bat rehabilitation center in Ukrainewho filmed mating pairs, and with Jan Jeucker, a bat enthusiast and citizen researcher, who filmed hours of footage of serotonin bats in a church attic in Netherlands.
In total, the team analyzed 97 mating events – 93 from the Dutch church and four from the Ukrainian bat rehabilitation center. The results are published in the journal Current Biology.