Last updated: September 17, 2015
A local resident discovered this gray fox and reported it to our biologists. | Photo: National Park Service
When the National Park Service released an image that showed the famous Griffith Park mountain lion known as P-22 suffering from mange and disclosed that he had been exposed to rat poison, biologists hoped the unfortunate news would raise awareness about the harmful impacts of common household poisons on our local wildlife population.
This week’s report of a dead gray fox brought home how far we have to go in educating the community about the unintended impacts of using these products around homes, parks, and businesses.
A local resident called on Monday to report the dead animal, found on private land near Peter Strauss Ranch in Agoura. Although the findings are still preliminary, the necropsy indicated that the gray fox likely died as a result of exposure to anticoagulant rodenticide (this is the more formal term for the rat poisons that use blood thinners to kill the animal). The gray fox had internal bleeding and did not have any signs of other trauma (such as injury from a vehicle, other animal, etc.). Testing the liver for poison residues will help confirm the cause of death.
National Park Service researchers have documented widespread exposure to anticoagulant rodenticides since they began studying carnivores in and around the Santa Monica Mountains in 1996. The graphic below summarizes this research and shows how the poison works its way up the food chain.
Despite the fact that we’ve only studied a limited number of gray foxes, this is not the first time we’ve documented the poisoning of a local gray fox. Back in 2008, biologist Joanne Moriarty conducted a necropsy on GF-29 (the “GF” stands for gray fox), an animal she had first caught near Westlake Village.
In that case, the animal had such significant internal bleeding that blood was actually coming out of its ears and mouth (anticoagulants block the vitamin K cycle, which is critical for allowing the body’s blood to clot).
GF-29’s ear shows signs of external bleeding and bruising. Anticoagulant rodenticides interfere with blood clotting. | Photo: National Park Service
Although these photos and details can be disturbing (and these are the sanitized photos that do not show blood throughout the abdominal cavity and elsewhere), it’s critical that the public understands the unintended consequences of using these poisons.
So please share this blog post with others and learn about controlling rodent populations without the use of anticoagulant rodenticides.
Although we think P-22 has recovered, it’s likely that he continues to be exposed to poisons left out by local residents and other property owners.
Let’s see what we can do to change that.