By: Nadia Steinzor, Carnivore Conservation Director
Throughout history, humans have had a penchant for killing wildlife they perceive as dangerous, in the way of agriculture, homes, industry, and other development, or simply bothersome. After eliminating the immediate threat, a person may feel safe and in control. But since this approach is terribly cruel, ecologically harmful, and ultimately ineffective, aren’t there better ways to address human-wildlife conflicts?
This question guides Project Coyote’s work to shift public attitudes from fear to respect and policies from lethal control to coexistence. Extensive science demonstrates that persecuting coyotes actually increases conflicts by encouraging greater reproduction and opening territories to inexperienced, juvenile dispersers prone to seek food like garbage and unprotected domestic animals.
Similarly, there is growing evidence that the indiscriminate killing of mountain lions doesn’t reduce conflicts with people and could exacerbate them by breaking apart family units. Research has also shown that over time, lethal measures don’t prevent conflicts with black bears, which are primarily driven by food availability and ecological conditions.
With such facts in mind, Project Coyote is now tackling a misguided approach to human-wildlife conflict that occurs close to home for many: the widespread use of rodenticides to eliminate mice, rats, and other rodents.
In addition to causing slow, agonizing deaths for the targeted creatures, these toxic chemicals sicken and kill foxes, coyotes, bobcats, owls, hawks, and companion animals that eat them. Impacts include internal bleeding, paralysis, seizures, and organ failure. Animals can suffer for days or weeks.
Even human children are at risk if they ingest rodenticide bait, which often comes in bright colors and shapes that resemble candy. According to the American Association of Poison Control Centers, nearly 8,300 such exposures were reported in 2023. Toxicity studies indicate that symptoms can include vomiting, internal bleeding, and neurological disturbances.
The pernicious effects of rodenticides occur across the food chain and broader environment. In 2024, the California Department of Fish and Wildlife released comprehensive data confirming that dozens of wildlife species have been exposed to rodenticides, including 100% of coyotes and red foxes, 95% of mountain lions, 67% of black bears, 54% of raptors, and 91% of raccoons that were tested. Last year, hunters in the state were warned about rodenticides in animals killed for food after the discovery that the chemicals can turn the flesh of wild pigs blue.
As the rampant risks of rodenticides come to light, some states are adopting laws to limit how and when they can be used. After a successful coalition effort to secure passage of the nation’s first restrictions in California, Project Coyote and partners are actively drafting and advocating for bills in Colorado, Vermont, Massachusetts, and elsewhere that would greatly restrict the use of several types of rodenticides. While exemptions can exist for public health emergencies and certain agricultural purposes, new laws and regulations would go a long way toward reducing harm to animals and the toxins in our shared environment.
As with all types of strategies to reduce human-wildlife conflicts, there are ample nonlethal, safer, and more effective alternatives to direct killing—particularly because mice and rats reproduce rapidly and can have larger litters after group members have been killed or experience other pressures.
The first line of defense is always exclusion and prevention—whether keeping foxes away from backyard chickens, coyotes away from sheep, or mice out of kitchens and basements. Key steps to make human spaces less attractive and inviting include:
- Containing human food and garbage and not leaving out bird seed or pet food.
- Sealing openings in walls and around plumbing and installing wire mesh and other barriers around foundations and vents.
- Trimming down ivy and cover plants near buildings where rodents can shelter.
In the instances when removal becomes necessary, live trapping can be considered. Emerging methods of birth control substances for rodents (such as the products Evolve and ContraPest) show promise in reducing local rodent populations. Practiced together and over time, these different nonlethal methods can be highly effective in reducing local rodent populations.
Coyotes and other carnivores provide many ecological benefits, including maintaining balance across the food chain. It is a tragic irony that in the quest to kill rodents, we’re also harming many of nature’s most effective rodent hunters. Ending the use of toxic rodenticides reduces suffering and encourages us to coexist with our wild neighbors, large and small.
Stay up to date by joining Project Coyote’s E-Team to stand up for wildlife, advance coexistence, and help end the use of harmful rodenticides.
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