In 2017 Wesley Sarmento became the first ever prairie-based bear manager for Montana Fish, Wildlife & Parks.
Sarmento’s job entailed regularly putting himself between local residents and massive grizzly bears and he recently published a research paper detailing his 7-year search for the most effective hazing methods to avoid conflicts between grizzlies and humans.
Sarmento used several hazing methods throughout his tenure with Montana FWP including off-road vehicles, guard dogs, non-lethal projectiles like rubber bullets and cracker shells but the most effective deterrent proved to be a high tech solution, a drone equipped with thermal imaging cameras.
Excerpt from Wesley Sarmento research paper “Drones Outperform Dogs For Hazing Bears: A comparison of Carnivore Aversive Conditioning Tools”:
“I conducted a six-year study of the efficacy of non-lethal hazing tools to deter grizzly bears (Ursus arctos) away from people on the prairies of North-Central Montana. I tested a new technology, drones, and traditional methods of hazing bears including dogs, projectiles, and vehicular pursuit.
These various hazing techniques were successful at stopping undesirable bear behaviors and caused a significant increase in avoidance behavior and distance to human infrastructure. Results from these 163 hazing events suggest aversive conditioning may have occurred over longer time scales as older bears required less hazing and hazing events decreased over each calendar year.
Drones outperformed other hazing techniques where the odds of a pursuit of a bear being possible increased 127% relative to vehicular chasing due to accessibility issues. Relative to vehicular pursuit, dogs required high maintenance and had an 86% reduction in the odds a hazing event would be successful relative to vehicular pursuit. Grizzlies fled to locations that were farther from roads and human development.”
The study was conducted between July 2017 and July 2023 across Montana’s northern prairie region. For each of the 163 encounters, researchers recorded detailed data of each grizzly bear including age, sex, group size, initial behavior, and response to hazing tactics. A successful hazing event was defined as the bears moving at least 200 meters away from their initial location. The research team used GPS pinpoints and aerial mapping to measure distances bears traveled and their direction of travel.
Drones proved to be the the most effective hazing tool with a 91% success rate, followed by vehicles at 85%, projectiles at 74%, and dogs at 57%. While drones proved most effective at hazing bears in the open terrain of prairie environments, they may not be as useful in densely forested areas where abundant obstacles would make drone operations much more difficult. Additionally weather conditions like precipitation and high winds could inhibit drones effectiveness.
Wesley Sarmento research proves that under the right conditions drones can be a safe and effective non-lethal hazing tool for wildlife management teams. If you would like to read the entire research paper, please do so here.