LOUISVILLE, KENTUCKY—No rancher likes to think of their cows sharing space with a lion, or even an impala. But that may be the best way to save Africa’s big game, according to a study reported here this week at the annual meeting of the Ecological Society of America. The counterintuitive approach could help the livestock—and therefore ranchers—as well.

“There’s potential for it to be a win-win situation,” says Steven Seagle, an ecologist at Appalachian State University in Boone, North Carolina, who was not involved with the work.