Endangered snow leopards and rare Himalayan wolves may be giving conservationists in Nepal a new kind of headache. Although both species prefer dining on wild prey, a new study shows they consume far more livestock than realized, a burden on the migrating herders who let their goats, yaks, cows, and horses wander—often unaccompanied—in the region’s mountain pastures. To find out whether the wild predators were helping themselves to the occasional domesticated animal meal, scientists collected 573 scats from 182 leopards (Panthera uncial, shown above) and 236 scats from 57 wolves (Canis lupo chanco) at 26 sites spread across 5000 square kilometers of mountain terrain in the Annapurna and Manaslu conservation areas. Their genetic analysis showed that wild blue sheep called bharal comprised 57% of the leopards’ diet, whereas small mammals such as marmots and hares made up the bulk of the wolves’ meals, at 41%. The canids also ate Tibetan gazelles and other ungulates, which made up 31% of their diet. Next on the list was livestock, making up 24% of the wolves’ diets and 27% of the leopards’, the scientists report today in PLOS ONE. The spotted cats seem to prefer horses and goats, whereas the wolves favor goats, horses, cows, and yaks—an animal the leopards avoid, perhaps because of its size. Males are the primary livestock killers, possibly because females are more wary, the scientists say. The findings come as no surprise to the scientists, who predicted that the predators would eat more livestock when wild prey was scarce—a behavior common to big wild cats like tigers, lions, and cougars. But they also worry that the predators’ taste for domesticated animals will make it harder to protect them from humans seeking revenge. One solution? Building up the populations of the leopards’ and wolves’ wild prey.