Biochemist: “During the yearly breeding season, male lemurs rub the glands on their wrists against their fluffy tails and then wave them at females in a behavior called ‘stink flirting.'”
TOKYO — Would you be caught on a date without some cologne or perfume? The right or wrong scent can make or break a romantic meeting among humans, but a new study finds we’re not alone in that regard. It’s just been discovered that male ring-tailed lemurs emit a fruity and floral smell from their wrists when they notice an attractive female nearby.
The research team, from the University of Tokyo, used a detailed chemical analysis to detect the three pheromone compounds that produce the smell. These findings are quite noteworthy; this is the first time ever pheromones have been found in primates.
“During the yearly breeding season, male lemurs rub the glands on their wrists against their fluffy tails and then wave them at females in a behavior called ‘stink flirting,'” says senior author Kazushige Touhara, professor and biochemist at the University of Tokyo, in a release.
Smell is a big part of lemurs’ lives in general. They have highly developed scent glands on their shoulders and wrists. Most of the time, these glands help communicate a variety of traits such as social ranking, personal territory, and reproductive status. Now it appears that male ring-tailed lemurs also use their glands to earn the attention of potential mates.
“Since only ring-tailed lemurs have these wrist glands and exhibit ‘stink flirting’ behavior, we reasoned that specific odorants for sexual communication must be involved,” Touhara explains.
While observing a group of these lemurs, researchers noticed that female lemurs were sniffing the “scent markings” left by males much more often and for longer periods of time during breeding season. This time period, of course, is when female lemurs tend to be particularly receptive to sexual advancements.
So, they decided to gather perfume samples from four males and present the smells to females individually. The female lemurs sniffed the fruity smells for twice as long as they usually would during the sexual off-season. Additionally, during the off-season, males secrete a bitter-smelling scent instead of a fruity one.
“Females sniff the floral and fruity scent for a few more seconds than the controls and occasionally even lick it. Although this sounds like a very short time, it’s enough to recognize or evoke curiosities in the male,” Touhara adds.
To better understand the origin of the scent, the research team performed a complex analysis and were able to figure out the three major chemical components responsible for the wrist-glands’ fruity scent. While all three were also present in the more bitter-smelling scent during the sexual off-season, all three were present in much larger amounts during breeding season. Interestingly, females only seemed to respond to the compounds when all three were mixed together. Each one individually didn’t seem to interest the female lemurs.
“All three compounds have been suggested to be involved in the recognition of newborn sheep by their mothers, and tetradecanal is known as a sex pheromone in some insect species. Although this is the first time 12-methyltridecanal has been identified in primate species, all three aldehydes appear to be used as communication tools widely throughout the animal kingdom,” Touhara says.
Younger males in the prime of their life produce more of these compounds than older males, probably because testosterone production naturally tapers off with age. Moreover, older females past reproductive age didn’t seem to respond at all to the fruit scent. All in all, the research team are confident they have discovered the first case of pheromone use among primates, but say further research is still needed to fully understand the smell’s full impact on lemurs’ sexual behaviors.
“While we have not examined behavioral changes after the sniff in detail, this is an area for future work to determine whether these pheromones impact mating success,” Touhara concludes.
The study is published in Current Biology.