Can drones help prevent deadly bear attacks?

By Stephen Beech

Deadly bear attacks can be prevented by drones, according to new research.

Unmanned aerial vehicles are the "magic tools" needed to chase killer grizzlies away from people, say American scientists.

Drones are far more effective than dogs at "hazing" - or distracting - the giant beasts, according to findings published in the journal Frontiers in Conservation Science.

Brown bears roam across much of the northern hemisphere from the mountains of Spain to the prairies of the United States.

They are formidable meat eaters and carnivores that can weigh up to 751 kilos (1,656 lb) and have claws 15 cm (6 in) long and long canine teeth that can easily crush bones.

Conservation biologist Wesley Sarmento, a grizzly bear management specialist in Montana, said: "All these powerful features make brown bears an imposing predator that can take down prey as large and dangerous as an adult bison."

"Yet, while these bears eat meat, much of their diet is plant-based because they are omnivores.

"Brown bears have very few dietary restrictions. This large dietary breadth, however, causes them to seek out many of the same foods that humans consume.

"So, just about anywhere you have brown bears and people, you have human-bear conflicts."

Brown bears, also called grizzly bears, have been a protected species in the US since the 1970s, which has led some populations to expand.

Sarmento said: "The return of the grizzly to the Great Plains has been hailed a conservation success story but has come with the unintended consequence of increased human-bear conflicts.

"Some people are upset with having to live with such a fearsome animal.

"Grizzlies can kill livestock, people, and cause property damage.

"Fortunately, people are not on the typical bear menu and attacks are extraordinarily rare.

"Nevertheless, their presence makes all these risks possible, and therefore, it is essential for wildlife managers to prevent these conflicts and resolve issues quickly when they do occur.

"Addressing people’s concerns over grizzly bears is necessary for the successful long-term conservation of the species."

Sarmento, who in 2017 became the first bear manager based entirely on the Great Plains, said: "Resoundingly, people said they didn’t want bears near homes, in town, or damaging property, namely livestock.

"This seemed like a reasonable request, so I offered to haze bears away.

"Hazing is the act of the chasing an animal away from an undesirable place or stop it from doing a specific behavior, like attacking livestock.

"Some people jumped at the idea and offered to help, while others were skeptical."

He started collecting data to test if it worked.

Sarmento said: "I wanted to know if hazing was effective at moving bears away from undesirable places.

"In addition, I wanted to know if it taught grizzlies to stay away from people long-term, which is called aversive conditioning.

"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.

"One day, I got a call about a bear in some trees near a family’s house.

"I drove out to the farm on that rainy day to chase the bear off so the kids and livestock would be safe.

"My truck, however, was limited by the wet ground - I couldn’t drive up to where the bear was because I would get stuck.

"So, I went out on foot, shooting the firecracker-like cracker shells from my shotgun.

"The big, agitated male grizzly didn’t take kindly to my hazing work and charged out at me.

"Luckily, I was able to stop the large bear with a well-placed cracker in front of him, which spun him around and caused him to flee.

"After that risky encounter, I decided to get a widely touted, but scientifically untested tool – bear dogs.

"A month later I had two adult Airedales, known as the king of terriers, to help me haze grizzlies.

"I picked this type of dog because the local people favored the breed and conservation outcomes are supposed to be more successful when those local perceptions are considered.

"It didn’t take long for me to realize that the bear dogs weren’t all they were hyped up to be.

"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.

"Often they went after feral cats and porcupines. I tried relentlessly to better train the dogs, but the effort had little effect.

"Realizing the dogs weren’t a miracle solution, I decided to try a more technological approach that had also never been tested before – drones.

"Equipped with a highly maneuverable, buzzing drone I was scattering bears with accuracy.

"I could precisely chase bears exactly where I wanted them – all from the safety and comfort of my truck.

"The unmanned aerial vehicle was exactly the magic tool that I had been needing.

"Even at night, I could find bears from afar with the thermal camera, and then fly in closer to move them away from towns, homes, and livestock.

"The drone was such an asset that I couldn’t imagine doing the job without it."

Sarmento added: "Even though all the tools had some success at moving bears away from people, the drone performed notably better than dogs.

"With the drone, I was no longer limited by fences, canals, and other obstacles that would’ve stopped me or limited my range with the other tools.

"All the hazing work seemed to pay off. Older bears required less hazing, and the number of hazing events declined over each calendar year – evidence that long-term aversive conditioning was occurring.

"Bears appeared to learn to stay away from people.

"The aversive conditioning likely prevented some conflicts from occurring, which meant bears would be less likely to get into trouble. It was a win-win."