When preparing for a date, a human might use a small spritz of cologne or perfume. And male ring-tailed lemurs also splash on some cologne to impress the females. The only difference is they secrete their own scents from glands near their wrists. And during the breeding season, the males rub the secretions from their wrists onto their tails, and then wave the tails near females. Researchers actually call this behavior “stink flirting.”
Biologists already knew that lemurs have scent glands and that they use them to communicate their social rank or to identify their territories. Scientists also knew that sometimes males use their scent glands as part of a dominance display against potential rivals. But nobody had really looked to see whether the females were relying on the males’ scents as part of their mate selection process.
Nobody until Kazushige Touhara, a biological chemist at the University of Tokyo. Working at a wildlife laboratory, he and his team collected the secretions from male ring-tailed lemurs’ wrist glands twice a month for several years. In an email he described the males’ scent as “fruity and floral.” The researchers identified three chemical compounds in the secretions that were in higher concentrations during the breeding season—which suggested that these chemicals, all of which are long-chain fatty aldehydes, might be involved in mating and reproductive behaviors.
After identifying the three compounds, the researchers soaked cotton balls in a variety of smelly substances, then offered them to female ring-tails. And the lady lemurs spent more time sniffing cotton balls that were infused with the three aldehydes. Especially during the breeding season.
More research is necessary to be sure, but Touhara says this is the first time a sex pheromone has potentially been identified in a primate. The findings are in the journal Current Biology. [Mika Shirasu et al Key male glandular odorants attracting female ring-tailed lemurs]
While none of these three compounds have yet been identified in the secretions of any other primate, they have been found in lamb wool. Their presence implies that these substances might help newborn sheep recognize their mothers. And one of the chemicals also acts as a sex pheromone in two different types of insects. Which means that these kinds of long-chain fatty aldehydes are likely used widely throughout the animal kingdom for social communication. No wonder they’re often used in the colognes and perfumes we humans pay through the nose for.
—Jason G. Goldman
(The above text is a transcript of this podcast)