If you’ve ever applied a fragrance to yourself before heading out, you’re not alone: deer, elk, goats, rats, bears, hedgehogs and monkeys all do this. In some cases, it’s rather disgusting – the European hedgehog, for example, covers itself in a pungent mixture of toad skin, soap and feces as a form of scent-based camouflage. Capuchin monkeys aren’t much better, using onions and squashed bugs to provide themselves with anti-parasitic ointments.

Lemurs were already known to partake in a bit of fragrance application, but new research from Duke University reveals that the fragrance alchemy of ring-tailed lemurs stands head and shoulders above the rest. As revealed in the journal Royal Society Open Science, they are able to synthesize colognes that are unusually rich and persistent.

“Our subjects – adult, male ring-tailed lemurs (Lemur catta) – have a complex scent-marking repertoire,” the authors note in their study. It seems that these highly social, particularly vocal primates are exceedingly aware of the chemistry of their own effusions, knowing which substances will trap in which aromas.

Unlike other animals, male ring-tailed lemurs can produce scents using glands on their chests, which secrete a thick, foul-smelling, brown paste. They also have wrist glands that are capable of manufacturing a fast-evaporating fluid with a musky aroma. These curious fellows can either use these scents on their own (“pure” scents) or they can combine them with each other (“mixed” scents).

^{Male ring-tailed lemurs wafting their unique stenches at prospective mates. BBC Earth via YouTube}

Captive lemurs, located at the Duke Lemur Center in Durham, North Carolina, were previously seen to use these pure and mixed scents to serve a variety of purposes, from marking territory to “outstinking” a male competitor. In the case of the latter, they smear mixed scent on their tails before waving them at each other, wafting their disgusting clouds into the air in the hope of incapacitating their opponent.

To clarify why lemurs mix their scents rather than always use pure scents, researchers presented a variety of secretions to 12 of the captive ring-tailed lemurs at the reserve, and observed their reactions. One wooden rod contained wrist secretions, one contained chest secretions, and one contained a mixture of both.

During this bizarre olfactory buffet, the researchers noted that lemurs tended to prefer the mixed secretions, spending longer periods of time sniffing them. Even after the scents were left exposed to the air and allowed to evaporate for 12 hours, the lemurs still frequented the third rod, switching from sniffing to licking it.

Clearly, mixing the scents increases their longevity. The greasy chest secretions contain a chemical called squalene, a viscous oily substance commonly used as a preservative in human perfumes and skincare products. By including it in scent mixtures, even the most volatile aromas are able to be locked in.

The team also think that by mixing the scents, the amount of biological information conveyed by scent increases. Individual scent mixtures are, chemically speaking, quite strikingly different, which allows each ring-tailed lemur to convey a truly personal, unique aromatic signature. And, just like humans, these rather unpleasant lemur fragrances are also used to attract mates.

Although the females cannot produce these scents, these inventive perfumiers still have a way of making their presence known. On occasion, they’ve been seen to raise their tail and urinate, just a bit, on the ground, in order to mark territorial boundaries.