A study conducted by a team from the University of Toronto (U of T) Scarborough observed a unique ritual performed by male ring-tailed lemurs that help with their chances of securing a mate. This practice has been dubbed ‘scent flirting’ and seems to add to the already complex lives that these distant relatives of humans lead.

The scent is an important aspect of a lemur’s social structure. Researchers have now identified a ritual where a dominant male lemur will rub his tail on his scent glands and flash it at potential a potential mate, only to be met with aggression from the group. But, over time, male lemurs who did this had a greater success of finding a partner.

"Stink-flirting displays are done more often by dominant males," says Amber Walker-Bolton, lead author, and instructor in U of T Scarborough's Department of Anthropology in a university press release.

"This behavior is also very costly because these males are met with higher levels of aggression than if they were to do other types of scent-marking, so there's definitely something unique about this type of behavior," she added.

These ring-tailed lemurs are Strepsirrhines, a sub-order of primates who share a common ancestor with humans. Research of these animals has already revealed a complex social structure and fascinating group dynamics. Females dominate the group. Like other lemurs, they huddle in large groups in order to keep warm and maintain social bonds, with lower ranking males often excluded from most social activities.

Males are known to use their scent glands to mark territory and often engage in so-called 'stink-fighting' displays where they rub their tails in their scent before wafting it at an opponent, said the release.

When the dominant male does es waft his scent at a female lemur, he is often met with aggression from other females and members of the group. The researchers, for the first time, examined these displays and their role in terms of male rank and female mate choice.

"One morning I was watching a huddle and saw an outsider male approach and try to waft his tail to a female. Well, right away he was met with all this aggression from the group, and it made me question why they would go through this just to be met with a negative result," says Walker-Bolton, who did her field research at the Berenty Reserve in Madagascar.

The study published in journal American Journal of Primatology, said that only dominant males from inside a group and outside, engaged in this ‘stink-flirting’ behavior. As observed in lemurs, less dominant males are often left out of social practices. The team observed that outsider males performed the ritual at a much higher rate than insiders. But, they were also met with much higher rates of aggression from females and other males.

"It could be a way for them to show their rank or it may simply be an alternative mating strategy in terms of transferring to a new group to gain mating opportunities," says Walker-Bolton, who also served as a consultant on the IMAX film Island of Lemurs Madagascar.

"One thing is for sure, there's a lot of aggression directed towards them, and it's a costly thing to do since it can end in such a gruesome fight."

The team measured the rate at which female lemurs presented themselves which was the barometer for how effective these displays were.The study showed that receptiveness of the female was linked to the number of ‘stink-flirting’ display the male made. This proved that males who engaged in a greater number of stink-flirting displays were presented to more often and were more successful in finding a mate.

Walker-Bolton says the next steps for this particular study is to see if there's a correlation between these displays and reproductive success.