MAN VS. BIRD

California Biologists Deploy Drones to Battle Ravens Slaying Baby Tortoises

A dedicated team of California biologists is working to reach high-up ravens nests in new ways.

A team of biologists, computer experts, and certified drone operators are using unmanned aerial vehicles to quell a surging raven population in Southern California’s Mojave Desert. The ravens have waged an inter-species battle with desert tortoises, particularly their young. Since 1990, the number of desert tortoises in the region has plummeted by more than 90 percent due to a number of factors. However, ravens have compounded the threat by targeting the youngest generation of tortoises. To fight back against the highly intelligent scavengers, scientists have turned to drones which can help them access nests perched hundreds of feet above the ground. The team uses a long-established method of “egg oiling,” which involves removing fertilized eggs from a nest, coating them with corn oil, and then placing them back in the nest. The oil prevents oxygen reaching inside the egg, effectively killing the embryo in a relatively humane way. The novel approach requires scientific collecting permits and a dedicated work force, as raven populations grow every year.