Photo by Maria Dryfhout/

Flying drones used in research projects cause stress in black bears

Share This Story!

Drones are increasingly being employed in research projects to observe wildlife, but the unmanned aerial vehicles may be causing more harm than good.

A new study published in the journal Current Biology found that flying drones caused the black bears to become stressed and drastically raised their heart rates.

Lead author Mark Ditmer, who is a postdoctoral researcher in conservation biology at the University of Minnesota, said he expected the bears to run away when followed by the machines. But when approached by the drones, the bears actually remained still and showed signs of stress.

“I couldn’t believe it,” Ditmer said to the CBC. “It became strikingly obvious that we were seeing a pretty acute stress response that was pretty severe, at least in some cases.”

In one case, a mother bear with her two cubs was so stressed by the buzzing drones, her heart rate increased 400 percent over her resting heart rate.

The study noted that drones have potential to revolutionize the way wildlife is studied. Drones can “access remote or difficult terrain, collect large amounts of data for lower cost than traditional aerial methods, and facilitate observations of species that are wary of human presence.”

And yet, Ditmer says this study should act as a “cautionary tale” when developing drone best practices and regulations in scientific studies .

While each bears’ heart rates indicated a stress response during all flights, they rarely induced a change in behaviour. To the untrained eye, this could suggest that the bears are undisturbed by the drones but their heart rates suggest otherwise.

“Just because we’re not noticing an animal changing behavior, that doesn’t mean there’s not some sort of negative response happening.”