When ravens are killing desert tortoises, it's drones to the rescue

Baby desert tortoise. The desert tortoise is a federally listed threatened species only found in the Mojave Desert. Credit: U.S. Geological Survey. 

In the Mojave Desert, there's a battle between ravens and threatened desert tortoises (plus their allies: conservationists and U.S. government officials). Until recently, the ravens were winning. But they may have met their match in the form of drones equipped with a liquid oil that prevents the raven eggs from hatching.