Fruit bats use oral sex to prolong the deed

Scientists say behavior represents an X-rated first for adult non-humans

By Charles Q. Choi
Special to LiveScience

updated 2:16 p.m. ET Nov. 2, 2009

When they do their thing, female Chinese fruit bats add oral sex to get the males to prolong the act, scientists now find, suggesting the behavior confers evolutionary benefits.

Oral sex, or fellatio, is often used in human foreplay, the researchers noted, but rarely seen in other animals. As such, there have been few evolutionary reasons given for oral sex to date, and fellatio is largely thought confined to humans, although juvenile members of the chimpanzee-like bonobo do it for play.

Now scientists find the short-nosed fruit bat (Cynopterus sphinx) routinely engages in oral sex, the first time fellatio has been seen in adult animals other than humans. The researchers argue the act likely has evolutionary benefits.

Scientists at the Guangdong Entomological Institute in Guangzhou, China, and their colleagues investigated bats they captured at a nearby park. Although bats comprise the second largest order of mammals at more than 1,100 species, little is known about their mating habits because of their nocturnal lifestyle and their often-inaccessible roosts. The researchers were originally expecting to watch behaviors such as grooming or the construction of tents from Chinese fan-palm leaves.

"We did not expect fellatio in fruit bats at the beginning," said researcher Libiao Zhang, a biologist at the Guangdong Entomological Institute in Guangzhou, China. "We were also surprised at how often it occurred."