Calvin Klein’s famous fragrance, Obsession for Men, is marketed as having a “musky base” and musky certainly is right: When sprayed on camera traps, it's known to keep wild jaguars lingering so scientists can observe them for research.

Biologist Allison Devlin, a research associate at Panthera—an organization that works to conserve wild cat species around the world—says that what attracts big cats to the scent is not its “citrus notes and exotic spices” nor its “hint of seductive mystery,” to quote Sephora. It’s actually the perfume binder, a synthetic version of civetone, a derivative of the chemical ketone that’s produced by the civet, a nocturnal carnivore.

“[Civets] produce civetone in the pheromone that they’ll deposit through the glands near their rectum. They’ll rub that against trees to mark their territory or to attract mates,” said Devlin in an interview. “It’s this very thick yellow [substance with a] very pungent scent that gets deposited,” she added. “I think it's that content that elicits curiosity from cats.”

Obsession for Men’s effect on certain big cats was first reported in 2003 in CAT NeWS where it was written that, in 1998, a zookeeper from the Dallas Zoo sprayed some of her boyfriend’s cologne into an ocelot exhibit as a type of “behavioural enrichment,” said Devlin.

In 2005, a group of scientists from the nonprofit Wildlife Conservation Society were working with big cats at the Bronx Zoo, conducting perfume trials to figure out which scents would encourage cheek-rubbing in cheetahs, ocelots, snow leopards, and Amur tigers in order to apply their findings in the field. (Cheek-rubbing is a natural behaviour, according to Devlin, when big cats rub their cheeks against the scent to leave their own scent on top.)

The researchers found that captive male cheetahs spent an average of almost 15 minutes in contact with objects sprayed with Obsession for Men. This finding was then applied to jaguars over the course of a few different studies.

At the Toronto Zoo, zookeepers use various scents for enrichment purposes when working with animals, wrote Hollie Ross, a wildlife care supervisor at the zoo, in an email.

“Some are natural like spices, extracts and blood, while others are synthetic, such as perfume. The carnivores especially tend to react to various scents by rubbing on the item where it was placed,” she wrote. “As far as using scent to keep an animal in a certain area, that is absolutely not our intention.” Scent enrichment is used, she explained, “to promote and elicit natural behaviours.” Devlin told me that the use of “scent lures” is widespread in the study of wildlife. “Since big cats are so elusive and naturally rare, we use a variety of non-invasive techniques like camera trapping and hair snares to study their populations,” said Devlin in a follow-up email. “Researchers may sometimes apply a scent lure to a camera trap, for example, in the expectation that the unusual scent will pique the cat's curiosity and the cat will linger in front of the camera trap.”

This longer observation period gives scientists a better chance of identifying individual jaguars by the rosette patterns on their fur, which are unique as a fingerprint, Devlin explained.

She added that jaguars are drawn to Obsession for Men because they’re curious and want to mark their territory by adding their own scent through cheek-rubbing.

Now, perfume is expensive (one 120 mL bottle of Obsession for Men costs CAD$95 at Sephora) so scientists have found ways to make the scent last. “I’ve seen folks who have sprayed a patch of carpet, then fixed that to the tree or near to the camera trap,” Devlin told me. “They’ve sprayed cotton balls, put them in a film canister, then put that on the ground or fixed it to the tree.”

Devlin said the maximum amount of perfume she’s seen used has been four sprays’ worth, or up to 5 mL of the scent, per camera trap station. That works out to about $4 per station.

To avoid spending an entire research budget at Sephora, Devlin says she thinks most researchers have either had the perfume donated, or have the funding in place to test different scent lures. “I know it’s pretty expensive,” she said. “The cost effectiveness is something you have to take into consideration when doing this kind of study.”

The good news is that jaguars’ attraction to the perfume isn’t so strong so that you have to fear going to zoo on a date after dousing yourself with it. There are enough competing fragrances in a place like that, Devlin said, to throw jaguars off your trail.