"Feral burros wreck wetlands in the desert national park. But a study found that when mountain lions prey on them, the donkeys may help some terrain thrive."
"Early on a June morning in Death Valley National Park, a wild donkey brought her foal to one of the springs scattered throughout the desert. Two sets of eyes watched the foal pick its way through the brush. One set belonged to a mountain lion, the other to a trail camera.
Footage of the subsequent kill was published last month in the Journal of Animal Ecology, in a study that provided direct evidence of mountain lions hunting donkeys in the western deserts of North America. The attacks don’t just result in donkey scraps and full cougars, researchers argue: They suggest that native carnivores act as an important check on nonnative prey. The study also raises questions about how damaging donkeys are in the wild desert landscapes where they are found, although federal wildlife authorities maintain a goal of eliminating them entirely.
Donkeys originated in North Africa but were introduced to the United States through the mining industry in the late 1800s. Federal agencies were not pleased to see the hardy herbivores establish themselves in Death Valley. In the 1930s, wildlife managers began culling donkeys, arguing that herds of burros trampled vegetation, muddied springs and drove away native wildlife like bighorn sheep. But the donkeys have persisted, and decades later, an estimated 4,000 live in Death Valley, despite National Park Service goals of bringing the population to zero."