Results were announced for the Great Grévy’s Rally held in Kenya in January. The Princeton-sponsored event used 40,000 photos collected by 500 volunteers to precisely quantify the remaining wild population of the world’s largest and most imperiled wild horse species, the Grévy’s zebra (pictured). The initiative was among the first to use “citizen scientists” to establish the population and range of an endangered mammal. (Photo by Morgan Kelly, Office of Communications)
Kenya’s endangered Grévy’s zebra is down to a population of just 2,350 animals in the wild, according to an innovative “citizen science” counting project organized by Princeton University and other institutions from Kenya and the United States. That’s down from 15,000 in the 1970s.
Grevy’s zebra, a larger and leaner equid than the stout and ubiquitous plains zebra found in much of southern and eastern Africa, is threatened by human encroachment, overgrazing by livestock and poor land management. Less than 1 percent of the animal’s territory is protected.
The counting project, called the Great Grévy’s Rally, was among the first campaigns to use data collected by members of the general public to establish the population and range of an endangered mammal species. Hundreds of volunteers collected 40,000 photos of the zebras. The photos were analyzed using specially developed pattern-recognition software to identify individual animals.
Princeton professor Daniel Rubenstein, who helped develop the identification system, noted the primary benefit of the rally was to provide a precise accounting of the zebras’ numbers and improve actions to protect the species.
