Breeding Cheetahs

National Zoo researchers (with Ume) are experimenting with cheetah fertility. Jessie Cohen/NZP, SI

It's dinnertime and Tumai swoops into her den, bares her teeth, grabs a cow bone from a plastic dish and disappears with it into the tall grass behind her. Tumai is an 8-year-old female cheetah whose name in Swahili means "Hope." She and Zazi ("Fertile"), a 7-year-old female, moved into the National Zoo's new Cheetah Science Facility this past September.

"We thought they might be stressed by the new environment, but they took to it right away," says biologist Adrienne Crosier, who runs the nine-acre complex. It is part of the National Zoo's Conservation and Research Center, a 3,200-acre facility in the foothills of Virginia's Blue Ridge Mountains where some 30 species of rare or endangered animals—North America's black-footed ferret and Asia's red panda, Eld's deer and clouded leopard, among others—are studied and bred.

"What we have is space, and minimal public disturbances," says David Wildt, head of the zoo's Center for Species Survival and an authority on cheetahs. "The cheetahs are able to focus on why they're here."

They are here to breed. Within the captive cheetah population of 225 in the United States and Canada, the death rate has exceeded the birth rate during 10 of the past 12 years. The center's near-term goal is to make cheetahs self-sustaining in captivity. The long-term goal, says Wildt, is to "have it all"—to improve captive cheetahs' meager genetic diversity with sperm from wild cats and to use sperm from captive cheetahs to impregnate females in the wild.

Last year, Crosier went to Namibia and, with Laurie Marker, grew embryos in a lab; they hope to implant them into cheetahs within two to three years. By the end of this year, Crosier expects both Tumai and Zazi to give birth after artificial insemination via frozen sperm from two Namibian males. "There have been a lot of advances recently to improve the survivability of sperm after thaw," Crosier says. "At the same time, we have found that older females like Tumai can still produce good-quality eggs." In 2004, Tumai produced the first cheetah litter ever born at the National Zoo, and Zazi gave birth to five cubs the next year. Both litters were sired naturally.

The new cheetah center can accommodate up to ten females, in individual enclosures, and four males, alone or in groups. The females' yards flank a central avenue known as "lover's lane," where males parade so that the females can choose their partners from among them.

Virtually all cheetahs in the United States are descended from South African animals, and their genes are probably even less diverse than those of wild cheetahs. Breeding cheetahs—whether via lover's lane or artificial insemination—is highly problematic, but the rewards, Crosier says, are priceless. "This is where you get to save a species. This is where you get to make babies."

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