Drones are helping tortoises survive in the USA's Mojave Desert. Tortoises there are under threat from ravens. The raven population in the Mojave has increased by 700 per cent in 25 years. This has been a disaster for the desert tortoises. A local conservationist said that in some places where there used to be 10 ravens, there are now 15,000. They could completely wipe out the tortoises, whose numbers have fallen by over 90 per cent since 1990.
Technology may rescue the tortoises. Biologists have a plan to reduce the raven population, using drones and a technique called "egg oiling". This involves drones removing fertilized eggs from raven nests, coating the eggs in corn oil, and then replacing them. The oil blocks the egg's oxygen and so ends the life of the embryo inside. A biologist said: "If ravens figure out that their eggs are rotten, they are likely to...nest someplace else."