According to a new study, the endangered ring-tailed lemurs (scientific name: Lemur catta) from Madagascar engage in "stink flirting" to attract mates during the breeding season.
To impress female lemurs, the males wipe the smelly chemicals that they secrete from their wrist glands onto their fluffy tails, which they then waft to the potential mates they are wooing. Elizabeth Pennisi reports that researchers have identified three chemicals secreted by the male lemurs that they use to stir the females' interest.
When it is not breeding season, the male's wrist secretions are leathery and bitter. They use these secretions mainly to repel other males. When breeding season comes, however, the secretions become sweet, tropical, and fruity. The researchers painstakingly collected this "cologne" for laboratory chemical analysis with the use of tiny pipettes that gather minuscule amounts of the secretions before they evaporate.
From the chemical analysis, the scientists identified three molecules responsible for attracting females. They published their findings in Current Biology journal this week. The chemicals they found are 12-methyltridecanal, tetradecanal, and dodecanal, which are odorants known as aldehydes; one of these is said to be the sex pheromone in insects, while the other smells like a pear.
On every object that the researchers sprayed these chemicals, the female lemurs were prompted to spend more time sniffing and licking the sprayed objects. They only did this, however, when it is breeding season, and they only did so when all the three chemicals were sprayed. The research team also noted that the production of the perfume mixture was correlated with levels of testosterone in males.
According to the research team, the response of the females to the cocktail suggests that it could help males find mates. These are chemicals are candidates for the first primate pheromones to be known to science. The scientists add, however, that the term "pheromone" cannot be officially used yet without more evidence.
University of Tokyo biochemist and lead author Kazushige Touhara says that beyond demonstrating how the female becomes interested in the odor, they don't know what other effects may be. They still have to definitively show how the perfume enhances mating before they can say that these chemicals indeed qualify as a pheromone.
Lemurs have scent glands on their genitals, shoulders, and wrists, deploying them to improve their social status, start and resolve a fight, and attract females. Complementary to this, they have a vomeronasal organ known as Jacobson's organ, which helps in discerning scents.
According to the University of Oxford pheromone expert Tristram Wyatt, he is optimistic that the findings of Touhara's team could be the first primate pheromones discovered by science. He says that they are promising candidates, but also added that scientists currently do not know if these chemicals affect lemurs' breeding.
Touhara discloses that the responses they got from the female lemurs after they sprayed the breeding musk from the males are a topic for future research that his team wants to explore. Touhara notes that that the lemur's fruity, floral love potion smelled "pretty good."