The Stillaguamish Tribe of Indians is helping to expose an unintended consequence of a common practice: using bait boxes to eliminate rats and mice from around buildings.
These black boxes—resembling a large lunch pail or small tackle box—can be seen tucked alongside homes, apartment complexes, shopping centers and farm warehouses. They contain material that rodents like rats and mice are enticed to chew on, which over time is intended to lead to fatal internal bleeding.
The key ingredients are anticoagulants, chemicals known as blood thinners when used medicinally for people.
Recently, the Stillaguamish Tribe’s wildlife program learned that the deadly rodenticide from bait boxes is making its way into the Northwest food chain, having the intended fatal hemorrhaging effect on unintended animals including the protected bald eagle.
“Anticoagulant rodenticides poison these creatures as well as many others, threatening their survival and our cultural heritage,” said Gary Tatro, a member of the Stillaguamish Tribal Council and the tribe’s wildlife policy representative. “We can do better. They deserve better.”
For the Stillaguamish and in broader Coast Salish culture, the eagle is spiritually significant. The bird is also an emblem of the United States and protected nationally under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. For these reasons, tribes, states and federal agencies collect eagle carcasses and investigate the cause of death when warranted.
The Stillaguamish Tribe and Washington Department of Fish and Wildlife send locally recovered eagles to the Washington Animal Disease Diagnostic Lab in Pullman, at Washington State University, for analysis. Of six bald eagles sent to that lab since March 2024, five had hemorrhaging indicative of anticoagulant ingestion. Four were confirmed to have a deadly accumulation in their organs of anticoagulants used in rodenticides.
These eagles came from different areas of Snohomish County around Arlington, Darrington and Stanwood, indicating the risk of wildlife exposure to anticoagulant rodenticide is not centralized around one source area.
The Stillaguamish Tribe is interested in continuing to investigate the impact on eagles and other wildlife species that eat mice, rats and other rodents that have been poisoned. The hope is to further substantiate the issue and promote safer alternatives for rodent management.
“We are concerned with this issue because bald eagles and other species are important to the perpetuation of our culture and we are committed to managing, protecting and conserving treaty resources,” said Sara Thitipraserth, a Stillaguamish tribal member and director of the tribe’s natural resources department. “We would like to draw attention to this emerging concern and promote alternatives because the widespread use of anticoagulant rodenticides may have broader implications to ecosystem health.”
With anticoagulant rodenticides, the targeted rodents die slowly, becoming easy prey for bald eagles and other predators, which then ingest the chemicals.
“There are dangers to these rodenticides,” said Jennifer Sevigny, wildlife program manager for the Stillaguamish Tribe. “This isn’t just an eagle issue, it can affect anything that consumes a dying rodent or scavenges a carcass.”
The unintended impact on wildlife has been documented around the world, from vultures in California to owls in Australia. One U.S.-based study published in September 2024 called the trend a “threat for raptor conservation worldwide.”
“It’s really widespread,” Stillaguamish wildlife biologist Amanda Summers said. “If you walk around almost any building, you see those little black boxes; strip malls, gas stations, they’re everywhere.”
Alternatives do exist. Summers said the tribe has had success deterring rodents from its offices and vehicles using a variety of plug-in and solar-powered ultrasonic devices. Sevigny said deploying rodent birth control is another option.
“I think a lot of people, if they knew about the dangers of anticoagulants, would try something else,” Sevigny said.
Above: Bald eagles are among the wildlife being killed inadvertently by the common use of anticoagulant rodenticides. While one of these birds is clutching a duck for dinner along the Skagit River in January 2021, eagles often hunt or scavenge rodents as well, which can pass along poisons consumed at bait boxes. Photos and story by Kimberly Cauvel.
