Research has shown that drones don't bother marine mammals, but the jury is still out on whether and how much they might harm other mammals.

Photo: Jake Gaviola/Unsplash

Drones are increasingly common tools for scientists who study wildlife, allowing them to get to places that might otherwise be physically or financially impossible to reach. But drones, or unmanned aerial vehicles (UAVs) don’t always go unnoticed by animals, and there is growing concern that drone flights might be disrupting the animals they’re being used to study.

Fortunately, researchers at Aarhus University in Denmark have found that UAVs don’t bother marine mammals such as dolphins and whales, which rely heavily on echolocation to navigate and find food. They tested this by placing a microphone about a meter below the ocean’s surface and flying drones over it at various altitudes. The result was that the sound from the drones didn’t carry into the water and that it essentially fades into the normal background noise of water at that depth.

Normally, marine mammals don’t spend much time at a depth of just one meter, so if the sound doesn’t disturb them at that depth, it certainly won’t do so at greater depths.

It also seems that the noise the drones make is outside the range of hearing for most marine mammals.

The question then becomes, do UAVs harm terrestrial mammals, birds, and insects? It’s clear that bats and birds would probably face the most challenge from these aerial vehicles, but as yet there have not been any studies about the impact of drones on these species. Researchers will need to perform similar studies to ensure that their drones are safe for use with different types of wildlife.

“Wildlife research is carried out under very strict permits, and we hope that our research will help guide the regulators who evaluate permit applications to ensure that we understand what may or may not have an effect on these animals,” says researcher Lars Bejder, who leads Murdoch University’s Cetacean Research Unit in Western Australia.