Peacocks make fake sex noises to attract the attention of females, according to scientists.
The birds have a wide variety of calls, including a distinctive hoot during mating. When a male peacock has successfully attracted a female, it rushes at her while making this noise and attempting to mate.
Scientists have observed male peacocks making this noise when they are out of sight of females.
Despite not being in close proximity to the male, Canadian researchers found females would be attracted to the ‘lek’ or mating area by the sound.
"It's much louder than it needs to be to communicate with just the female that the male is trying to mate with," Dr Roslyn Dakin from the University of British Columbia, Canada, who co-authored the study told the BBC.
Dr Dakins studied birds living freely and unmanaged in zoos and parks across North America.
She found that the birds may have learned that this deception attracts more females.
"We know that sound increases the chance a female will come around and visit the male but what we don't yet know is whether males get any fitness benefit from that," she said.
By faking the mating call, the males could potentially persuade females they are more sexually active and fitter than other males.
The faking males were also the most prolific breeders in the groups.
Surprisingly, a third of all mating calls were ‘faked’, which Dr Dakin described as "astonishing" as the signal could end up being completely ignored by females after hearing it too many times.
"Theory predicts that when faking happens a lot, the receivers should stop listening to the fake signal at all” Dr Dakin said. “So what is it that's allowing this deception to persist at such a high rate?"
Her research will now focus on whether there are any direct reproductive benefits to faking for male peacocks, the BBC has reported.
The study is published in The American Naturalist.