Drones Increase Heart Rates Of Wild Bears. Too Much Stress?
RENEE MONTAGNE, HOST:
Wildlife biologists have become big fans of unmanned aerial vehicles, commonly known as drones. Instead of struggling through rugged terrain to get the animal they want to study, they can just send in a drone with a camera. Of course, it's not known exactly how animals feel about drones. NPR's Nell Greenfieldboyce reports that scientists recently set out to answer that question.
NELL GREENFIELDBOYCE, BYLINE: Mark Ditmer is a wildlife ecologist at the University of Minnesota in St. Paul. He says as drones get cheaper and more available, everyone in biology seems to have new ideas for how to use them. For example, one of his colleagues wanted to fly drones over a big marsh to locate the nests of sandhill cranes.
MARK DITMER: And it makes his life so much easier if he can not have to go on foot through thick vegetation to find these things.
GREENFIELDBOYCE: But Ditmer is more interested in how drones could affect the animal's life.
DITMER: What's the effect on the individual when we have this drone, you know, flying in close and kind of watching them?
GREENFIELDBOYCE: He realized he could explore this by flying drones over some black bears in Minnesota that were already being monitored for a different study. These bears were outfitted with both GPS locators and small implanted heart sensors...
DITMER: ...That record every heartbeat continuously throughout the year.
GREENFIELDBOYCE: So his team got ahold of small, off-the-shelf flying helicopters.
DITMER: They sounded a little bit like flying weed wackers.
GREENFIELDBOYCE: And programmed them to make short flights over the bears. They managed to do 18 flights over four bears, and what they found is that a visit from a drone made a bear's heart beat faster.
DITMER: One of them was a 400 percent increase from about 41 beats per minute to over 160 beats per minute.
GREENFIELDBOYCE: This happened even though video taken by the drones showed the bears acting blase.
DITMER: We need to be aware that just because we can't, you know, visually see an effect, that it doesn't mean that there's not some sort of stress response going on.
GREENFIELDBOYCE: Ditmer says one bear, foraging in a cornfield, did run away for maybe 15 feet, but then stopped...
DITMER: ...And watched the drone circle overhead.
GREENFIELDBOYCE: This study appears in the journal Current Biology, and it's left Ditmer with a lot of questions.
DITMER: We don't know if bears or other species can habituate to having drones flying over them.
GREENFIELDBOYCE: He says that's really important to know.
DITMER: Right now it's, you know, just getting started, but I guarantee you in 5 to 10 years, it'll just be commonplace to be using them for many aspects of research and conservation.
GREENFIELDBOYCE: But so far, there's been hardly any research into how wild animals react to drones. Nell Greenfieldboyce, NPR News. Transcript provided by NPR, Copyright NPR.