Researcher Mark Ditmer has tracked black bears for years in northwest Minnesota using heart monitors and satellite collars, and the bears barely noticed.
That changed, though, when he started experimenting with a drone. The bears were not pleased.
Flying a small craft over four bears in his study, he saw their heart rates spike in each of the 17 flights. Rates returned to normal soon after the drone left the area. Ditmer said it’s clear the bears were stressed by the drones. …
Ditmer says his findings, published today in the journal Current Biology, offer clear evidence that animals are stressed by drone flights even if they don’t run away or show an obvious response.
Ditmer’s bears don’t live in a remote forest. They are exposed to noise from farm equipment or vehicles on roads. While other researchers have looked at animals’ behavioral response to drones, Ditmer says this is the first close look at an animal’s physiological stress response.