Part of Wesley Sarmento’s job at Montana’s state wildlife agency was to scare grizzly bears away from neighborhoods and farm fields. He drove trucks toward them, honked horns and shot deterrents like rubber bullets and bean bag shells. But he often found these standard non-lethal hazing tools to be lacking.
“I actually ended up getting charged by a grizzly bear, and very nearly could have got injured or even worse,” he said. “At that point, I decided I needed to try something different.”
He bought two dogs, Airedale Terriers, but after a few months, he realized they weren’t great at chasing the bears away. Sometimes they went after other animals like prickly porcupines. Then, one day, when he responded to a call of a grizzly bear and three cubs eating wheat in a farmer’s field, Sarmento decided to try flying a drone above them.
“I launched the drone from the safety of my truck, started flying it towards them, and very quickly, they reacted and were fearful of the drone and started running away,” he said.
As predators like grizzly bears and gray wolves expand their ranges or are being recovered to more habitats, wildlife managers in the Mountain West are increasingly tasked with preventing conflicts between the animals and people or livestock. Some are turning to new strategies and technologies, including drones.
“The end goal is to allow people and wildlife to coexist, and that's basically keeping animals out of trouble and keeping people safe and their property safe,” said Sarmento, now a PhD student at the University of Montana.
He decided to put the drones to the test. In a research study of 163 hazing attempts in Montana over six years, he found that drones worked 91% of the time to chase grizzly bears at least 200 meters away. The drones performed better than other non-lethal hazing options.
But, Sarmento noted, the sample size was small and the differences in performance were not always significant. The results were published this year in the journal Frontiers in Conservation Science.
There were other practical reasons the bear managers opted for the drones. They were able to usher the animals to specific spots and avoid physical barriers on the ground.
“With the drone, we could fly over canals, rivers and fences, where we would have been completely stopped with all these other tools,” Sarmento said.
Still, he said more research is needed as the technology is new and developing. For example, he wondered whether drones work better in prairie environments compared to dense forests.
Meanwhile, wildlife managers are testing drones to prevent conflicts with other species. In Wyoming, they’ve been used to herd elk out of hay fields. In Colorado, the state wildlife agency was awarded a $15,000 grant to evaluate drones for identifying and counting wolves, as well as to scare them away from livestock. An agency spokesperson said researchers would evaluate wolves’ responses to drones and whether they change over time.
This story was produced by the Mountain West News Bureau, a collaboration between Boise State Public Radio, Wyoming Public Media, Nevada Public Radio, KUNR in Nevada, KUNC in Northern Colorado, KANW in New Mexico, Colorado Public Radio and KJZZ in Arizona as well as NPR, with support from affiliate newsrooms across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting and Eric and Wendy Schmidt.
