One of the rarest carnivores in North America lives in Washington’s Cascade Mountain Range: the Cascade red fox. This unique, mountain fox is adapted to alpine and subalpine habitats of the Cascades, endures harsh winters, varying snowpacks, and rugged terrain; yet its presence is waning. One increasingly relevant threat is anticoagulant rodenticides.

What are Anticoagulant Rodenticides?

Rodenticides are a type of poison that are designed to kill rodents such as voles, mice and chipmunks–several of the main prey sources for foxes and other carnivores. These poisons work by traveling through the body to interfere with blood coagulation, clotting, and cause spontaneous bleeding. The poison remains volatile in rodents beyond death: a carnivore that consumes the rodent either as prey or from scavenging a carcass can also be poisoned. Sometimes the volume is small enough that it simply makes the animal sick, but often, the secondary poisoning will cause mange or death.

Impacts to Cascade Red Foxes

Cascade red foxes have been observed displaying symptoms of poisoning and their carcasses have been found in recreational areas of Washington’s National Forests. Wherever there is an abundance of humans, we find an abundance of rodents, as rodents are drawn to the excess food and garbage that comes along with human habitation in these wild places. In order to control rodent populations, resorts and recreational sites will set out rodenticides underneath and around buildings and other structures that foxes may use for protection while raising young. When rodenticides are used in places with known foxes, the foxes could be impacted.

Cascade red foxes are a prey generalist that eats a diversity of food items, including small and mid-sized mammals, insects, fruit, birds and carrion. Despite their generalist nature, their diet is mostly made up of small rodents that act as the primary pathway for the fox to be poisoned by rodenticides. When rodenticides are present in a system, all carnivores are affected, but species like CRF that are already vulnerable due to their small population numbers are especially impacted by rodenticides. The loss of a single breeding adult or kit could have severe consequences for the species’ survival. As recreation and development expand into alpine regions, the risk of exposure grows. ARs used around infrastructures such as cabins or ski resorts do not stay contained – they ripple outward into the food web, and unlike species with larger, more stable populations, the CRF has no margin for error.

Safer Paths Forward

Across the West, communities are addressing the fatal use o f rodenticides, and showing that there are alternative solutions to addressing rodent problems without poisoning wildlife.

Effective alternatives include:

Rodent-proofing buildings with exclusion barriers.
Reducing attractants by securing food, trash, and compost.
Mechanical traps in protective boxes to reduce and prevent bycatch of non-target species.
Rodent fertility control products like ContraPest, which in field studies reduced rodent activity by up to 94% when used alongside exclusion measures.

What You Can Do

Protecting Cascade red foxes and other wildlife starts with choices we can make in our own backyards:

Avoid rodenticides and encourage your neighbors, home owners association, and local businesses to support alternative solutions.
Support non-toxic pest management policies in your local city, county, and at state level by supporting legislation that restricts the use of the most dangerous rodenticides.
Volunteer or donate to wildlife monitoring and conservation projects, including efforts to protect Cascade red foxes.
Spread the word: many people simply do not know the impacts rodenticides have on wildlife
Contact Washington’s legislators to demand that rodenticides are immediately removed from Cascade red fox habitat and voice support for a state-wide ban.

By replacing these poisons with safer, effective alternatives, we can limit our impact and take tangible steps towards safeguarding its future, and support the CRF’s ability to persist in the Cascades for years to come.