An American bear manager has identified the “magic tool” for scaring grizzly bears away from people and property. It’s not a shotgun, truck or pack of dogs – it’s a drone fitted with a thermal camera.
Scaring bears, also known as ‘hazing’, aims to reduce human-bear conflict by teaching bears to avoid areas near people. This is increasingly important as federally protected grizzly populations expand out of US national parks and into nearby communities.
The rise in grizzly numbers is a conservation victory. However, successful long-term conservation will require government agencies to address people’s concerns over living near these large predators.
Grizzlies are formidable animals. They can weigh 750 kg (1,656 lb), have 15 cm (6 in) long claws and a bone-crushing bite.
While humans are not on a grizzly’s preferred menu, these bears eat a wide variety of foods. Unfortunately, this diet causes them to seek out the same foods as humans, drawing bears into human settlements.
“I wanted to know if hazing was effective at moving bears away from undesirable places,” says Wesley Sarmento of the Montana Department of Fish, Wildlife and Parks. “In addition, I wanted to know if it taught grizzlies to stay away from people long-term, which is called aversive conditioning.”
Over the course of six years, Sarmento collected data on the efficacy of non-lethal hazing tools. The traditional shotgun with cracker rounds, which flash and make a loud sound, came with notable safety risks.
“I went out on foot, shooting the firecracker-like shells from my shotgun,” recalls Sarmento. “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.”
A month later, Sarmento tried bear dogs, a widely touted but scientifically untested tool. Ultimately, the dogs proved to be unreliable despite efforts to train them.
Finally, Sarmento tried a technological approach.
“Equipped with a highly manoeuvrable, 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.”
Adding a thermal camera to the drone allowed Sarmento to use this tool at night and to detect bears well before they got close to homes.
“All the hazing work seemed to pay off,” reports Sarmento. “Older bears required less hazing, and the number of hazing events declined over each calendar year – evidence that long term aversive conditioning was occurring.”
Sarmento argues that his efforts likely prevented some human-bear conflicts, calling it a “win-win” for people and grizzlies alike.
The research is published in the journal, Frontiers in Conservation Science.
