For more than a decade, 225 motion-triggered cameras strapped to trees across the Serengeti have fired day and night, and the millions of photographs they produced were sorted one by one by hundreds of thousands of volunteers who had never set foot in Tanzania

For more than a decade, 225 motion-triggered cameras strapped to trees across the Serengeti have fired day and night, and the millions of photographs they produced were sorted one by one by hundreds of thousands of volunteers who had never set foot in Tanzania

A decade of wildlife surveillance across the Serengeti produced millions of images—but only crowdsourced patience could turn them into science.