Add Black Bears to the List of Things Terrified of Drones

August 15, 2015 Updated: August 18, 2015

It’s already an established fact that drones can be of great annoyance to humans: whether you’re the secret service, a California firefighter, or just a casual homeowner, the newly popular gadget can ruin your day any number of ways.

Now, animal scientists have proven that drones are also a nuisance, and even a terror, to wildlife. A group of researchers at the University of Minnesota strapped heartbeat monitors to four black bears and flew drones around them to test their reactions.

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The results, published in Current Biology, indicate that a single drone is enough to make the bears uncomfortable. The drones were programmed to take a five minute flight at a height of 65 feet above the bears. Even at such a distance, all four bears showed elevated heart rates in the presence of the drone, some of them severely.

Researchers saw one female black bear with cubs heart rate jump by 400 percent, from 41 to 164 beats per minute (bpm). Another female black bear that was in hibernation had her bpm jump by 56, and a 1-year-old male bear by 47.

The researchers performed this experiment under different conditions and saw that the increase in heart-rate was largest when the wind-speed was high, suggesting that the anxiety shown by the bears stem from being surprised by an incoming drone, whose buzz is covered by the wind, they can’t detect with their ears.

Bears exposed to the drones also exhibited greater than normal movement. One bear moved for nearly 1,900 feet in the 40 minutes after encountering the drone, which set a record for movement in such a short period of time for that bear. The black bear with cubs was also observed moving 4.2 miles within 28 hours of encountering the drone, into the area she had never visited before.

“Our results support the 2014 decision by the U.S. National Park Service to ban all public use of UAVs within park boundaries after a low-flying UAV caused a herd of big horn sheep in Zion National Park to scatter, separating lambs from their mothers,” the researchers wrote.

This is not the first study to examine how animals react to drones. An earlier experiment had drones approach ducks and flamingos; the birds only reacted to the drones when approached from above them.

Encounters with other birds have not gone so smoothly. A man flying a drone in the Australian outback had his device knocked out of the sky by eagle, all of it caught on camera.