A remote colony of birds kept flying away before anyone could count them, so a team of ecologists built a do-it-yourself aerial drone to spy on them from above.
The team made their drone out of a 4.6-foot-wide radio-controlled airplane, two cameras and a GPS tracking unit, all for less than $2,000.
It was the first time scientists have used an unmanned aerial vehicle to inventory a remote bird population, said ecologist and project leader Francesc Sardà-Palomera of Centre Tecnològic Forestal de Catalunya Solsona in Catalonia, Spain.
“If you want to use a real plane, you need to rent a pilot, rent the plane, pay for the fuel, everything. It adds up,” said Sardà-Palomera, who led the drone-assisted bird-counting study published online Nov. 7 in Ibis. “[The drone] is a great method and it’s very cheap.”
Aerial drones aren’t new. The army has used UAVs to spy on and sometimes kill enemies for years. Meanwhile, hobbyists enjoy the bird’s-eye view of their custom-built rigs. (Some have even lofted camera-equipped devices to the edge of space.)
A research group in 2006 pioneered the use of camera-packing drones to monitor hard-to-reach or easily disturbed wildlife populations, but found software and hardware incapable of gathering research-grade data. By 2009, however, the technology caught up. Another team used custom-built drones to count marine mammals such as beaked whales and Dall’s porpoises.
In 2010, Sardà-Palomera and his team found themselves frustrated by trying to count a remote population of rare black-headed gulls on a lagoon island in northeast Spain.
“You have to go with a boat, and when you’re just 100 meters from the colony, all of the birds start to fly away,” he said.
Borrowing designs used in the marine-mammal-tracking study, Sardà-Palomera’s team built their own drone. They bought a small wireless video camera and embedded it in the nose of a remote-controlled airplane to provide a live, first-person view for the pilot (video below). A downward-pointing camera continuously snapped 12-megapixel photos from roughly 130 feet up.
For 15 minutes at a time, they flew their electric drone over the lagoon and captured images of the colony without disturbing it. Following a soft landing, the team used the on-board images and GPS coordinates to inventory adult birds and their nests.
“We have been using it just about every week since this study,” Sardà-Palomera said.
Images and video: Copyright of Francesc Sardà-Palomera of Centre Tecnològic Forestal de Catalunya Solsona