Last September, a gray fox was found dead at a residence in Inverness in Marin County with no signs of trauma. Since the residence was adjacent to the Point Reyes National Seashore, the National Park Service investigated. The gray fox was sent to their lab in Colorado and found to have unexplained hemorrhaging in the brain and lungs with no signs of trauma. These are classic signs of anticoagulant rodenticide poisoning, so the liver was sent to be analyzed by the California Animal Health and Food Safety Laboratory in Davis. The liver contained a toxic combination of three different second generation anticoagulant rodenticides. These rodenticides – brodifacoum, bromadiolone, and difethialone – are only legally used by pest control professionals for rodent control in and around man-made structures. After eating these baits, rodents remain mobile for several days and can be eaten by wildlife or pets.
Members of the public cannot obtain these materials over the counter. Due to their harmful impacts to wildlife second generation anticoagulant rodenticides became restricted use materials in California in July 2014.
To protect local wildlife, the National Park Service and the California Department of Fish and Wildlife urge safer rodent control such as exclusion and trapping. It is also recommended that residents ask any pest control company that they employ not to use these materials on their property. The two agencies are teaming up to get the word out locally to prevent another incident near Point Reyes National Seashore. However, this is not a unique situation. Monitoring in California has found that the majority of predators and scavengers, such as foxes, bobcats, mountain lions, coyotes, and raptors, are still being exposed to these materials.
Be a good neighbor to your local wildlife and help spread the word!
To learn more, please visit the CDFW webpage: