The science of wildlife conservation is getting pretty complicated and technical, what with radio telemetry, satellite mapping, and DNA analyses. But sometimes, the best methods are the simplest ones, if you just know who to ask. The efforts by wildlife biologists to save the African cheetah are a good example.

Like many other big predators, cheetahs are in trouble. Being carnivores, they're at the top of the food chain, which means there aren't very many of them to begin with. In addition, they require large home ranges, which makes them sensitive to habitat destruction. In some regions, a large number of cubs are killed and eaten by lions and hyenas. And finally, cheetahs are persecuted by humans either for trophies and fancy fur, or as livestock-killers.

A major problem in trying to conserve cheetahs is that they are difficult to find and count. Unfortunately, estimates of numbers of animals and where they occur are vital statistics for working out how to save a species. One solution is to study a population in one area for a very long time, which is what Tim Caro did.

Professor Caro in the Department of Wildlife, Fish and Conservation Biology at UC Davis studied wild cheetahs in Tanzania's Serengeti National Park. This was no easy task, since cheetahs roam a huge area and are few and far between - one animal every 20 square miles, to be more precise. To obtain the most accurate counts, and to find out about the animals' social system, hunting habits, breeding patterns and so on, Caro and his colleagues documented the lives of the individual cheetahs in Serengeti, recognizing them by the characteristic pattern of spots on their tails. While this detailed study has provided invaluable data, it took almost twenty years to collect.

Unfortunately, conservation problems usually can't wait twenty years for an answer. Although cheetahs face many different threats throughout their range in Africa, there is little information on where exactly they occur and how many are left. Since we cannot afford the luxury of long-term studies in all sites, researchers turned to faster, cheaper techniques.

Ecologist Paule Gros, who received her doctorate from UCD working with Professor Caro, used several indirect methods to count cheetahs in ten regions in Kenya and Tanzania. For example, she estimated how much food (mostly gazelles) was running around, or (with Marcella Kelly, also of UCD) how much habitat was available, and then calculated how many cheetahs could be supported. In three of the ten regions, detailed studies, one of which was Caro's, had previously produced accurate counts of cheetahs. These "real" numbers were compared with the results of the indirect methods to see which ones produced the closest match.

Surprisingly, the most accurate method was the easiest and cheapest one: asking people, "Have you seen any cheetahs?" Within the protected areas, Paule Gros interviewed tourists, park employees, tour guides and biologists. Outside protected zones, in farmlands and range lands, she questioned farmers and cattle herders. When and where did you last see a cheetah? How many were together? Were there any cubs?

When compared with accurate counts from detailed studies, the interview method was about 88 % correct. The next best method - predicting cheetah numbers from how much food was available - was 63 % accurate.

Paule Gros conducted interviews in Kenya, Uganda, Malawi and Namibia, and used this wealth of information from local humans to assess the cheetah's current state of play in each country. While in Kenya, the species might just be holding its own, at between 1200 - 3350 animals, in other regions, numbers have declined, although estimate from Namibia are similar to those from Kenya. This study can be used to make recommendations to wildlife managers in the various countries.

The accuracy of the interview method was a surprise, but it wouldn't work for all species. Cheetahs are rare, charismatic animals, famous for being one of the fastest creatures on land. People notice them, and remember them. Furthermore, cheetahs hunt by day, out in the open. In contrast, interviewing people about leopards, who tend to be nocturnal, forest-living cats, would be much less successful.

We will always need long-term studies of individuals in order to manage animal populations properly. But in this day of disappearing wildlife, biologists must also employ fast, but accurate, ways of estimating numbers. In some cases, like that of the African cheetah, the humans who share the region with the animals could prove to be a gold mine of information.

© Kelly Stewart

Dept. of Anthropology, University of California, Davis, CA 95616
e-mail: kjstewart@ucdavis.edu

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