Pioneering Study Reveals Nonlethal Wolf Deterrents Effectively Protect Livestock Across Large Grazing Areas


Contact:          Leigh Anne Tiffany; (202) 772-0259;

             Suzanne Stone; (208) 861-4655;


After seven years of field research, Idaho's Wood River Wolf Project has shown that wolves and livestock can coexist on large grazing landscapes without lethal intervention. In a study published this week in the Journal of Mammalogy, a team of conservationists, biologists, United States Department of Agriculture and university scientists, veterinarians and ranchers in Idaho reveal that nonlethal techniques for managing interactions between wolves and sheep are more effective than currently accepted lethal protocols.

“This is the first peer-reviewed study using nonlethal deterrents to protect both livestock and wolves across a large landscape,” said Suzanne Stone, Northwest Senior Representative for Defenders of Wildlife and primary author on this study. “The results of the study challenge historic predator management at its core, showing that traditional government lethal predator control programs are substantially less effective than nonlethal strategies in protecting livestock even in large mountainous landscapes.”

Wolves were eradicated throughout the western United States by the 1930s, but are repopulating former habitats across the West due to protection under the Endangered Species Act.  Wildlife, including native predators, sharing the same space with livestock has resulted in deeply rooted conflicts. Traditionally, the federal government has assisted public lands ranchers by killing wolves and other native predators that threaten livestock operations. Nonlethal management strategies – including livestock guardian dogs, human presence near livestock, flashing lights, sirens and avoidance of wolf den sites – have been used on small-scale ranching operations, but have rarely been tried in large scale grazing operations.

The 7-year study covered grazing involving between 10,000 and 22,000 sheep across nearly 1,000 square miles of public land also inhabited by wolves. A total of 30 sheep were lost due to wolves during the entire period – 3.5 times fewer losses than adjacent grazing areas that depended more on killing wolves than these methods to coexist with them. While packs of wolves were killed in adjacent areas, not a single wolf was killed in the protected study area over the course of the 7-year study.

"If wolves and livestock can peacefully coexist in the remote mountainous terrain of central Idaho, they should be able to coexist almost anywhere,” said Stone.

The Idaho Wood River Wolf Project is supported by Lava Lake Land and Livestock, the Idaho Blaine County Commission, the Ketchum Idaho City Council, area sheep producers, conservation organizations, and local citizens. This study is a part of a Special Feature issue of the Journal of Mammalogy focused on predator control, specifically the growing benefits of using nonlethal techniques. The issue looks at how nonlethal methods are more effective at preventing depredation of livestock by large carnivores than lethal ones.


Corresponding author: Suzanne Stone, Northwest Senior Representative,





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