How do you keep track of one animal among many that look alike? For spotted hyenas, scientists read the coat. Each spotted hyena can be told apart by its spots, and all four hyena species have coat patterns that are unique and consistent throughout the animals' lives. Scientists who identify hyenas by their coats keep photographs of both sides of each animal, because the markings on the left and right sides differ.

Counting hyenas is hard. Common methods such as aerial transects and line surveys are not suited to them, because hyenas are seldom detected. Camera-trap photographs of individually recognizable animals let scientists estimate numbers by capture-recapture. That is a big step up over call-in and track-count surveys. Spots make it possible, since each hyena can be told apart by its spots.

Another team used sound. To count the hyenas around the Ethiopian city of Mekelle, researchers broadcast recorded hyena calls from five locations and counted the hyenas that came to the sound with night-vision binoculars. They estimated 210 hyenas.

Some hyenas are followed for years. As of November 2026, Berlin's Leibniz Institute for Zoo and Wildlife Research has monitored all the spotted hyenas of Ngorongoro Crater in Tanzania since 1996. That is eight social groups and more than 2500 individuals.

What do scientists know about how many there are? The IUCN Red List status of the spotted hyena is Least Concern (2014 assessment). As of November 2026, San Diego Zoo Wildlife Alliance gives a tentative world estimate of 27,000 to 47,000 individuals. Hyenas are the most numerous large predator in Africa where hoofed animals are common, which makes them an extremely important part of that ecosystem.

Counting is one way to learn about hyenas. Another is to ask what they eat. In a Kalahari study, 70 percent of what spotted hyenas ate came from animals they hunted themselves. Scavenging matters more when dead animals are plentiful and preferred prey are scarce. When hyenas eat animals that are already dead, they help clean up the places where they live. With spots, calls and cameras, scientists can know hyenas one by one.

Words to know

• transects: survey lines
• estimate: a careful guess
• monitored: watched over time
• unique: one only
• ecosystem: living community