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BLM Bans Lethal ‘Cyanide Bombs’ Used to Kill Predators

Ban in place on 245 million acres for minimum five years

M-44 “cyanide bombs” often indiscriminately injure and kill non-target species. These incidents have implicated more than 20 species of non-target wildlife, domestic dogs and humans, according to the Center for Biological Diversity. The federal agency Wildlife Services, which primarily uses the devices, says in 2018 alone it used M-44s to kill 6,579 animals. Photo courtesy Wildlife Services
M-44 “cyanide bombs” often indiscriminately injure and kill non-target species. These incidents have implicated more than 20 species of non-target wildlife, domestic dogs and humans, according to the Center for Biological Diversity. The federal agency Wildlife Services, which primarily uses the devices, says in 2018 alone it used M-44s to kill 6,579 animals. Photo courtesy Wildlife Services
by Julia Barton

In 2017, a child and family dog were on public lands just 400 feet from their Idaho home when they inadvertently triggered an M-44 cyanide device placed by a wildlife management agency. The incident injured the child and killed the dog, according to the Bureau of Land Management.

Cyanide devices have been used to lethally manage canids in the U.S. since the 1930s. M-44s are spring-loaded canisters of sodium cyanide that are topped with bait and staked in the ground. When target species—including coyotes, foxes, wolves and wild dogs—trigger the device by biting and pulling, the capsule ejects its contents into the animal’s mouth. The result is a dose of cyanide gas designed to kill within minutes.

Use of M-44s has been criticized by wildlife advocacy groups for years, and following a June petition, BLM on Nov. 22 banned the
The M-44 consists of a capsule holder, a cyanide capsule, a spring-activated ejector, and a stake. Bilingual signs warn about the device. Photo courtesy Wildlife Services
The M-44 consists of a capsule holder, a cyanide capsule, a spring-activated ejector, and a stake. Bilingual signs warn about the device. Photo courtesy Wildlife Services
devices on the 245 million acres of land it administers for a minimum of five years.

The petition—authored by the Center for Biological Diversity in collaboration with dozens of other conservation groups—emphasized that beyond inhumanly killing thousands of animals annually, the M-44 “cyanide bombs” often indiscriminately injure and kill non-target species. These incidents, including the 2017 Idaho case, have implicated more than 20 species of non-target wildlife, domestic dogs and humans, per the CBD. 

Also in 2017, Wildlife Services, the federal agency that primarily uses the bombs and is tasked with controlling wildlife that pose a threat to livestock or a nuisance to humans, released a report stating that more than 24,000 M-44 devices were deployed in 17 states from 2011 to 2015. It identified a total of 362 non-target animals from 26 different species as "accidental mortalities" due to M-44 devices during that time.
"According to a 2017 report from Wildlife Services, the program used M-44s to kill canids across 17 states with nearly 50 percent of the use in Texas."  – BLM Petition to Ban Use of Cyanide Bombs, June 2023
“Really any kind of scavenger species is attracted the smell,” CBD Carnivore Conservation Director Collette Adkins told Mountain Journal. “So raccoons, possums, bears, bald eagles and family dogs are all also attracted to these devices … leading to a pretty gruesome death by poisoning.”

Numerous other methods can be employed to manage canids in a more targeted and humane manner, Adkins said, including improved livestock husbandry.
"According its own data, in 2018 Wildlife Services used M-44s to kill 6,579 animals," reads a statement on the Center for Biological Diversity's website. "The victims were mostly coyotes and foxes, but more than 200 were non-target animals, including a bear, foxes, opossums, raccoons and skunks." Map courtesy CBD
"According its own data, in 2018 Wildlife Services used M-44s to kill 6,579 animals," reads a statement on the Center for Biological Diversity's website. "The victims were mostly coyotes and foxes, but more than 200 were non-target animals, including a bear, foxes, opossums, raccoons and skunks." Map courtesy CBD
The Environmental Protection Agency authorizes the use of M-44 cyanide devices for a select few federal and state authorities, including agencies in Montana and Wyoming. Less than 1 percent of the M-44 cyanide bombs deployed by Wildlife Services last year were on BLM-managed lands, according to a BLM statement on the decision.

“There's still a lot of public lands that could be subject to use of cyanide bombs,” Adkins said. “That's mostly Forest Service lands, but I think having seen that the BLM did the right thing, hopefully [other agencies] will too.”

Legislation banning M-44s on all public lands is pending, although, their use has been prohibited on National Wildlife Refuges and National Park Service lands, according to the BLM. The devices were previously banned in Wyoming, and currently state agencies in Idaho, Oregon, California and Washington ban or limit their use.

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Mountain Journal is the only nonprofit, public-interest journalism organization of its kind dedicated to covering the wildlife and wild lands of Greater Yellowstone. We take pride in our work, yet to keep bold, independent journalism free, we need your support. Please donate here. Thank you.

Julia Barton
About Julia Barton

Julia Barton is a freelance journalist and communications specialist based out of Bozeman. A Montana native, she earned a journalism degree from the University of Southern California and reports on the environment, outdoor recreation and the arts.
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