India, Oct. 23 -- Few animals vanish from a desert and then find their way back. The Asiatic wild ass did, with human help. According to a 2018 study in Conservation Biology, 28 wild asses were released into Israel's Negev from a captive herd between 1982 and 1987. Another ten were released in 1992 and 1993. Since then, the herd has grown, which sounds like a clear win. But a growing herd is not always a healthy one.

The Asiatic wild ass lived on the desert steppes of Mongolia, Russia, and the Arabian Peninsula. Today it survives in small isolated groups. In the Negev, it was gone by the 1920s, according to a 2013 article from Washington University in St. Louis. Because the animal could not be tamed, the local Bedouin hunted it for its m...