For as long as people have been creating organized communities, rats have been there to pick off the remains. As an invasive species, they're practically unparalleled in their success, much to the chagrin of the people living with them. But when they recently re-invaded Ecuador's Galápagos National Park, a new weapon proved extremely effective in the fight: drones.
While the Galápagos islands are historic for being the site of Charles Darwin's discoveries about evolution, other visitors have been less helpful. Rats first came to the Galápagos along with pirates or whalers sometime in the . While the exact timeline is unknown, they've done their damage over the years. They've and have laid waste to local fauna.
The rats were beaten back from the tiny North Seymour Island in 2007, but they found their way back ten years later. Since then, the challenge has been how to attack the rats without inflicting further damage on a very delicate ecosystem.
Drones provided an ideal solution. Painted blue to make them less noticeable to birds, they dropped poison pellets wherever rats were spotted. "The use of drones is more precise," says Karl Campbell, the South American director of the nonprofit group Island Conservation, in a . "It also increases feasibility, and reduces eradication costs of invasive rodents in small and midsize islands worldwide.”
Earlier this month, two six-rotor drones began lacing North Seymour and a nearby islet with rat poison. Each drone could carry 44 pounds (20 kilograms) worth of poison and fly around for 15 minutes. While one of the drones suffered a mechanical difficulty, according to , they were still able to cover half the island in valuable poison. The breakdown even afforded the chance for an experiment—workers spread the rest of the poison over the island by hand, allowing for an evaluation of the drones.
Drones can't cover every part of the land—for some remote islands, only a helicopter will do. But as Campbell tells Nature, “you have to have a helicopter for a month, sometimes shipped by boat. Your expenses very quickly add up.” Drones allow for more flexibility at a cheaper price.
Craig Morley, an invasive-species specialist at the Toi Ohomai Institute of Technology in Rotorua, New Zealand, says that the drones have a chance to change how scientists view conservation work. “You used to be able to see your opponent. Now, you just a press a button and you fire a missile,” he tells Nature, drawing a comparison between scientific and military drones. “You become a little bit detached from the reality that you have killed something or somebody over there.”
While it is important to keep that detachment in mind, it is unlikely anyone in the Galápagos will miss the rats too much.