Females define the cheetahs' unusual social order. Except when raising cubs, they are loners, and they select their mating partners. Males, meanwhile, form coalitions of siblings that hunt together and may remain together for life. In Namibia, males range over an area of about 860 square miles, while females travel farther—more than 1,500 square miles. Mothers have litters of up to six blind and helpless cubs. Perhaps to hide them from predators, cheetah mothers move their cubs to different dens every few days for the first six weeks of life (which makes tracking growing cubs difficult for researchers). Cheetah females reach maturity and leave the family when they are about 2 years old. No one knows for sure how long they survive in the wild; the animals live between 8 and 12 years in captivity.
In Namibia, 95 percent of cheetahs live on territory owned by ranchers. When Marker first got there, ranchers typically called cheetah "vermin" and killed about 600 every year. Marker's plan was simple. From the Windhoek airport, she traveled north in her Land Rover toward Otjiwarongo, "going door-to-door, talking to two farmers a day," she says, asking them how they managed their cattle herds, what they thought about the wildlife on their property and what problems they thought cheetahs were causing.
Marker shared her expertise as it grew. Cheetahs could not kill full-grown cattle, she explained, so ranchers might want to focus on protecting newborn calves. Cheetahs would rather eat wild game than risk an encounter with humans, she said, so instead of driving game away, ranchers should learn to live with it.
Her strategy emerged only gradually. "Here in Namibia we have wildlife, livestock and a unique ecosystem," Marker recalls telling the ranchers. "It is possible to make a living off every aspect of this, and you can have it all—if you have good livestock management. You can manage for predators, and you can make it work for profit."
By the time she had worked her way up to Harry Schneider-Waterberg's farm, she had filled notebooks with data. Schneider-Waterberg was in his mid-20s at the time, just starting to run the 104,000-acre farm that had been in his family for a century. "She told me that farmers with good management practices lost less livestock, and she had the facts to back it up," Schneider-Waterberg recalls. "I was young, just putting together my plan, and I thought if we can cut predator losses by doing these things, then I know where I'm going."
The best ranches, Marker told the ranchers, kept records for each animal, used herdsmen to spot cows ready to calve, then brought them into an enclosure until they did so. She explained that cheetahs won't come near donkeys, which can be extremely aggressive with other animals, including dogs, jackals and even leopards. She suggested using donkeys to guard cattle herds. "It was all information I could use," Schneider recalls, "never accusing." He now chairs the Waterberg Conservancy, a vast expanse of Namibian plains owned by 11 neighboring ranchers and the Cheetah Conservation Fund.
For the first few years, Marker camped in a succession of loaned farmhouses. In 1994, she bought the CCF property for $350,000 with grant money and a gift from a benefactor with ties to the Cincinnati Zoo. The property sprawls over 100,000 acres of savanna in the heart of cheetah country.
By that time, many of the ranchers had stopped killing cheetahs and were instead bringing those they had trapped to Marker, who took blood and semen samples from the animals, checked their age and health, and tagged and released them. Since 1991, Marker has done these work-ups on more than 800 cheetahs. She also established a sanctuary for motherless cubs; today it houses 46 orphans.
Marker's observations of cheetah behavior constitute most of what we know about them. She began fitting wild cheetahs with radio collars and following them with airplanes in 1992. She discovered that males, in groups, and females, which are solitary, roam over vast stretches of territory. Marker was the first to understand that females are the ones that select mates—a major reason why captive breeding had such a poor record: researchers had not known that it was ladies' choice, so giving single males a chance at several females—a standard breeding procedure—didn't work. She also learned that if two or more females occupy the same space, they may suppress each other's reproductive hormones. Today, breeders isolate females and let them choose mates from among the available males.
Marker also began integrated local education programs. There was not a lot of mixing between black and white students at first, Marker says, "but I polished up everybody's English. Soon the kids were all speaking American slang." Tribal leaders told her that the loss of even a single animal—cow, sheep or goat—to a marauding cheetah could cause great hardship. "If people are hungry," Marker says, "they could care less about conservation." In 1990, to help the African shepherds and goatherds, Marker consulted evolutionary biologist Ray Coppinger of Hampshire College, in Amherst, Massachusetts, who recommended she use guard dogs instead of donkeys, which are aggressive toward sheep and goats. Marker chose the Anatolian shepherd, from Turkey, a black-faced, cream-colored short-haired breed that weighs up to 130 pounds. In 1994 Coppinger brought four Anatolian adults and four pups to Namibia and helped Marker set up a breeding program. Over the years she has given away 280 puppies to ranches and communes all over the country.
Today Marker, who gets donations from around the world, supervises 13 full-time professionals and 25 support staffers. At any one time she may have a dozen or more visiting researchers, veterinarians and students on-site. She has scientific or educational ties to universities all over the world. At local high schools, her helpers teach kids about farm surveys and radio tracking, biomedicine and genetics, publicity and fund-raising. Under the aegis of the conservation agency Earthwatch, volunteers can take working vacations at the Fund, doing everything from fence-building to cheetah-feeding. Marker has powerful friends. Sam Nujoma, independent Namibia's first president, is the Fund's formally designated "patron," and Marker is currently the chair of the Conservancy Association of Namibia, the umbrella organization of Namibia's conservation-minded landowners. She also maintains an international cheetah studbook.