[LUM#1] Bird drone

[LUM Magazine] - Published on November 24, 2015 in Science-Society

How can wild bird populations be counted without disturbing them? Researchers at the Center for Functional and Evolutionary Ecology in Montpellier have found the solution...

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It's a strange bird hovering above the Camargue ponds: four motorized wings, metallic plumage, and a camera for an eye. A drone hums softly a few meters above the flamingos. Its mission: to count the birds. Ecologists have embraced this small flying machine, which allows them to take aerial photos to facilitate population censuses. More accurate than counting with binoculars and less expensive than using planes or helicopters, drones have everything going for them. "Using drones is fine, but it's essential to do so without disturbing the animals, "warns David Grémillet. The researcher at the Center for Functional and Evolutionary Ecology conducted the very first full-scale study to assess the impact of these aircraft on birds.

Respecting the well-being of birds

"We wanted to see how far we could go without provoking a reaction from them," explains Elisabeth Vas. For her master's degree internship in Information and Communication Sciences and Technologies for Ecology and the Environment, the young woman chose the start-up Cyleone, which specializes in drones. She organized more than 200 flights over the Camargue ponds to study the reaction of black-winged stilts and flamingos. "We varied the angles of approach, the speed, and the color of the drone. We also tried to gradually get closer to assess the distance at which the birds seemed disturbed by the drone's presence."

Results? To their surprise, the researchers were able to fly their aircraft within 10 meters of the flamingos without them showing any signs of stress. "This is probably because the drone does not resemble one of their predators, "suggests Elisabeth Vas. "Only when it approached vertically, directly above the group, did they turn their heads, as this is their blind spot," explains David Grémillet.

However,researchers point out the need for further studies to assess the birds' reactions more accurately. "It is possible that the birds experienced stress without us realizing it. To verify this, we would need to measure more precise parameters such as their heart rate and stress hormone levels," warns Elisabeth Vas, who also recommends extending the experiment to other species.

A multitude of applications on the horizon

Thanks to the protocols established, ecologists will be able to exploit all the possibilities offered by drones, and there are many: counting seabirds nesting in hard-to-reach cliffs, counting eggs in nests, reading rings that identify individuals, tracking migrations... all while respecting the welfare of the animals.