Listen up, guys. Or you might miss something important.
That’s the upshot of a new study on giant pandas’ mating sounds reported this week in the Proceedings of the Royal Society B. The study found that the high-pitched chirps of a female panda, which come once a year, tell their male suitors that they’re ready to mate. The discovery is the first example of a non-human mammal changing its voice to signal her fertility peak, and experts say it may help in conservation efforts of this critically endangered species.
“It’s been known for some time that around estrous, females begin to chirp,” Benjamin Charlton, an ethnologist at Zoo Atlanta and the lead author of the study, said in ScienceNOW. He wondered if female pandas’ vocalizations—ranging from growls to moans to bleats and chirps— got higher during their most fertile periods, as studies have shown women’s voices to do.
According to the ScienceNOW article, Charlton and fellow researchers recorded the chirps of 14 female pandas at the Wolong National Nature Reserve in Sichuan, China and monitored the female pandas’ hormone levels to determine the date of ovulation. The team found a distinct difference between the chirps females produced during the pre-fertile and the fertile phases of their reproductive cycles. The latter calls are longer, harsher, and more numerous, said Charlton.
And apparently, those fertile-phase sounds drive the guy pandas mad. Charlton and his colleagues used playback experiments at the China Research and Conservation Center for the Giant Panda in Sichuan to examine the response of male giant pandas to female chirps produced during the fertile versus pre-fertile times and found that the males could perceive differences that allow them to determine the precise timing of the female’s fertile phase. The research team played the two types of chirps for seven adult male pandas and videotaped the males’ responses.
“They spent significantly more time near the speakers pacing” when the chirps of fertile females were played, Charlton told ScienceNOW. “In the wild, such chirps may increase male-male competition.”
Click here to read about birds’ hearing during mating season.
