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- Gray wolf
Can drones haze wolves?
To stop predation on livestock in Oregon, researchers took to the skies
Wildlife managers are turning to the sky to keep wolves from livestock, scaring the predators away with drones equipped with speakers.
“We were able to effectively haze wolves away from cattle—and in one case—even stop an attack in progress,” said Dustin Ranglack, Predator Project leader at the U.S. Animal and Plant Health Inspection Service’s Wildlife Services National Wildlife Research Center.
This technology could become an effective, affordable and time-saving method to limit wildlife conflict without resorting to culling, Ranglack said.
The gray wolf (Canis lupus) population in southwestern Oregon moves between Crater Lake National Park and private and other public lands south of there. For several years, cattle ranches in the Klamath River Basin had experienced a number of wolf attacks on their livestock as the predators recolonized the area. For a period of 20 days in the summer of 2022, the Rogue Pack preyed on cattle 11 times—more than once every other night.
Tasked with managing the wolf-livestock conflicts, Ranglack and his colleagues at Wildlife Services struggled to keep up with the predators. While driving around on night watch, the team would either listen for wolf howls or respond to visual reports of wolves nearby sent through Wildlife Services or other agencies. They would directly engage the predators, chasing them out of the pastures and away from the cattle by foot or vehicle and making noise. But it was a difficult task catching up with individuals within the pack. The team wondered if just a “little more elevation” would help them get a clearer view of wolves approaching cattle from a greater distance.

Wolf drones
As a pilot test, Ranglack and his colleagues turned to drones to help them haze wolves in the Rogue Pack found in southwestern Oregon during the summer of 2022. They published their findings recently in Global Ecology and Conservation.
During their night watches, the team would go to areas where they expected wolves based on a combination of radio telemetry data from some collared individuals, reports from the public, and areas with documented wolf howls. The team spent much of their time sitting in their trucks all night with the windows rolled down, listening and scanning with handheld infrared cameras as they waited for action.
Often, the drone pilots would fly concurrently while the ground teams were surveying for wolf activity from their vehicles. When the team detected wolves or cattle behaving skittishly the pilot would fly the drone over to investigate. If wolves were present, the pilot would immediately start hazing the wolves away from the cattle.
They saw a lot of different activity from above, including elk (Cervus canadensis) and black-tailed deer (Odocoileus hemionus). They even witnessed bobcats (Lynx rufus) hunting rabbits. “You get to see some really neat stuff,” Ranglack said. Over the study period, they encountered wolves 51 times. Often, they scared them away.
Due to their work, the rate of cattle predation dropped from nearly one every two nights to only two cattle in the 85-day period when they tested these drones.
In one case, they actually managed to interrupt a pack preying on a cow. Two wolves were hanging off the steer’s hindquarters while a third circled around. “It looks like a schoolyard elementary fight,” Ranglack said. As the drone arrived, the wolves immediately made themselves scarce, and the cow only needed minor medical attention the next morning. “We know for sure there was a cow life saved because of the drone,” he said.

A voice from above
The drones didn’t always work effectively, though. During one interaction, the drone approached a wolf, and it dropped into a play bow, thinking the device was a toy, Ranglack said.
As a result, the team added speakers to the drones, which they used to shout at the wolves. The human voices were more effective than having no sound—the wolves turned tail and ran in these cases.
This study was only a preliminary test to see if the idea worked. Ranglack said his team is currently assessing what kind of noise might be most effective, such as the sounds of gunshots or AC/DC music.
One drawback to the drones was the short flight times—the team needed to change batteries often, for example. The researchers also needed licensed drone operators because the UAVs were not the cheap commercial types. The technique may also be less effective in areas that have a lot more forest cover.
“Now, we are more thoroughly evaluating it because it’s not a silver bullet,” Ranglack said.
However, he thinks the method is promising, especially as artificial intelligence gets better at identifying individual species like wolves and making autonomous flights. But determining the best way to employ them will require a lot more testing, he said.
Header Image: Wolves have preyed on livestock occasionally since they recolonized parts of southwestern Oregon. Credit: Oregon Department of Fish and Wildlife