Zoos looking to breed cheetahs in captivity are trying to get over a serious matchmaking roadblock. But giving bachelorettes a scented array of male urine might help improve breeding efforts.

“There’s so much information that passes through urine. It makes sense that it’s a conduit for [the cheetahs] to be able to make a choice on what would be a good mate,” says Regina Mossotti, director of animal care at the Endangered Wolf Center in Saint Louis, Missouri, and the lead author of a study published in June in Zoo Biology. Mossotti says her research is the first to show large carnivores can detect how genetically related an individual is to them based on the scent of its pee. The things she and her team learned could improve captive breeding programs and help to conserve the speedy felines.

Mossotti, who conducted the study as part of her masters degree research at Southern Illinois University, says that zoos hoping to breed the large cats generally attempt to arrange mating pairs with animals at other facilities in an effort to avoid keeping reproduction too much in the family. They use a matchmaking system that includes factors such as age and genetic similarity, but their calculations don’t always result in a mating success.

Cheetah females are notoriously hesitant to commit to a mate. And they can get aggressive—in the worst cases zookeepers have seen them fight would-be suitors to the death. At the very least, shipping the big cats around the country can be expensive and cause unnecessary stress for the animals, particularly if they don’t decide to mate.

In the wild male cheetahs have smaller ranges than females. They hunker down around prime real estate—such as a watering hole—that is likely to attract potential mates, according to Paul Funston, a senior program director for the global wild cat conservation organization Panthera, who was not involved in the research. Females, in contrast, wander far and wide, possibly staking out bachelors by sniffing the scent markings they leave around their territory before getting anywhere near a mating opportunity.

The researchers wanted to test the idea of using urine to introduce possible mates to one another in captivity. Mossotti drove around the U.S. collecting bottles of cheetah pee from potential mates at various zoos. The researchers then exposed 12 female cheetahs to samples from 17 male “urine donors” of varying genetic relatedness. They presented the females with the samples of two males at a time and assessed the big cats’ behavior. They found that females always spent more time in the vicinity of the pee from felines less closely related to them.

Urine can tell the females whether the male is unrelated, and if it’s ready to breed, Mossotti says. Although more research is needed, she hopes this interest in urine could translate to greater mating success.

Mossotti says it’s important for zoos to keep genetically healthy populations of vulnerable animals for potential future reintroduction, but also to help biologists learn more about the species to help with conservation efforts. “Cheetahs are a critically endangered species whose numbers are going down in the wild,” she notes.

Funston says the research is useful and has a good experimental design, but he doesn’t completely support using zoo breeding programs for these big cats, especially when the money might be better spent on conserving the animals in their natural habitat. “There’s not a lot of evidence that captive cheetahs can be successfully rewilded,” he says, but adds that there may be a better argument for the captive breeding of some subspecies, such as the Iranian cheetah, that are particularly endangered.

The pee smell test is only a first step, however. The next phase would be to present females with the urine of several unrelated males to see whether they show preferences, then bring them together in real life to see if the female chooses the same male as earlier scent tests predicted. Although this may take some work, she says the team’s research is already changing the way zoos think about managing their captive populations.