To Keep Us Safe From Bears, Drones Are Humanity’s Best Friend

Unlike their near relatives, polar bears, the majority of brown bears get most of their nutrients from plants – but that doesn’t make them cuddly. Also known as grizzlies, brown bears can bring down bison or moose when the mood strikes them, and their fondness for the same foods as humans just increases the chance they will investigate human habitation. Things might not have gone well for Goldilocks if found feeding on the three bears’ porridge, but a wild bear in a human house is almost as bad.

While some would argue the bears have prior claim on lands where conflict occurs, until bears can vote, that’s not likely to be the way the law sees it. Something needs to be done to stop booming bear populations in Yellowstone and Glacier National Park from strolling into nearby towns or homesteads – and in North-Central Montana, it’s Wesler Sarmento’s job to do it. Even if bears seldom attack people, perceptions are different, and if they’re seen too often the guns may come out.

Sarmento of Montana Fish, Wildlife and Parks attended enough town meetings to know he needed to keep the bears away from populated areas or livestock, and offered to deal with this by “hazing” them. Where survivors of fraternities and boarding schools might associate the term with having a bag thrown over their heads and being dumped at the crossroads in their underwear, Sarmento defines hazing in a guest editorial for Frontiers as; “The act of the chasing an animal away from an undesirable place or stop it from doing a specific behavior.” That’s probably more useful for a creature known to prefer appearing bare to wearing undergarments.

Sarmento admits he didn’t have experience in the bear hazing area, and had many skeptical locals to satisfy. “I started the program with the basic tools of any bear manager – a truck and shotgun with non-lethal deterrents, like cracker shells and rubber rounds,” he wrote. An encounter with a large male bear who didn’t take kindly to having cracker shells fired in his vicinity made Sarmento decide something better was needed. Pursuit in in a truck was safer, but not practical in all locations.

According to Sarmento, bear dogs are widely touted for bear hazing, but there is no scientific research on whether they work. He spent six years comparing dogs’ effectiveness with drones, cracker shells, and chasing in vehicles and recording the result so others could learn from his successes and failures.

If you’re questioning what use dogs would be against a creature that can weigh up to 750 kilograms (1,650 pounds), apply a thousand pounds per square inch of bite force, and have claws 15 centimeters (6 inches) long, take a bow. Certainly, the two Airedales Sarmento enlisted proved to be of little value, other than as ambassadors reflecting the popularity of the breed in the local area.

“Much of the time the two dogs couldn’t detect a bear that I could see across a field, or they chased whatever animal they discovered first,” Sarmento wrote. The consequences of that chasing including a porcupine can be seen below in a picture that really is worth a thousand words.

Encouraging as it was that the dogs had no fear, it was disheartening they also apparently had no brains.

Fortunately; “The unmanned aerial vehicle was exactly the magic tool that I had been needing,” Sarmento said, allowing him to deter bears from an area from the safety of his truck. 

“I could find bears from afar with the thermal camera, and then fly in closer to move them away from towns, homes, and livestock,” Sarmento added. “The drone was such an asset that I couldn’t imagine doing the job without it.” Moreover, as he noted, fences and other obstacles were no problem for the drone, which could also effectively control the direction in which the bear was herded.

Having immediately established the bears would run from the sound of the drone, Sarmento’s challenge was to see how long the experience lasted as a deterrent. He found; “The number of hazing events declined over each calendar year – evidence that long term aversive conditioning was occurring.” It appears that you can teach an old bear new tricks (young Airedales are a different matter), as the elder ursids needed fewer encounters with the drones to vacate an area permanently. 

In all, Sarmento attempted 163 hazing events, mostly in the breeding season (May and June). Drones had a 91 percent success rate, compared to vehicular pursuit (85 percent) and projectiles (74 percent). Drones’ only weakness seemed to be performance in high winds or rain. Sarmento admits in his paper that the reason drones work is unclear: “Does the humming of a flying drone sound like a swarm of angry bees, or is the novelty of a flying object enough to scare bears? Or perhaps egg eating bears have been conditioned by bombarding adult birds protecting nests?”

There were no reported injuries to bears or humans in the area over the period, although clearly the same cannot be said for dogs.

Scientific research depends on replication, so it would be good to see if bears in other areas, or perhaps times when food is scarce, can be similarly discouraged. Nevertheless, for those women presented with the recent viral question of whether to choose an encounter with a man or a bear in the woods, the best answer would seem to be to choose the bear, but take a drone.

The study is published open access in the journal Frontiers in Conservation Science