To Protect Wildlife It’s Time to End the Use of Dangerous Rodenticides

The use of rodenticides to control rodents has injured and killed hundreds or thousands of wild animals and pets throughout California. Many of us have seen the impact first-hand. While rodenticides are used to target rodents like rats and mice, predatory and scavenging mammals and birds are often secondary victims after consuming dead or dying rodents. Large mammals, like our iconic mountain lions, can encounter the toxins from preying on smaller animals that have consumed the target rodents as well. Even our pets are vulnerable to accidental exposure.

Throughout my time in the Assembly, I’ve worked to follow the science and end the use of the most dangerous rodenticides. Three years ago, I partnered with my colleagues Assemblymember Richard Bloom of Santa Monica and Senator Henry Stern of Calabasas to pass AB 1788 to minimize unintended poisonings from one subset of particularly dangerous rodenticides – second generation anticoagulant rodenticides (SGARs) – by placing a moratorium on certain uses until more comprehensive restrictions were developed.

The passage of the bill was remarkable for a couple of reasons. First, it took years and a lot of effort from policymakers and advocates alike to get the bill across the finish line, even though we’ve long known about the harmful effects of rodenticides like SGARs. Second, banning the use of the rodenticides hasn’t been enough to stop the devastation.

Recent evidence from the California Dept. of Fish and Wildlife (CDFW) suggests there is still widespread exposure and death to wildlife from SGARs and other rodenticides. In fact, a 2022 CDFW study found that 70% of the tested animals had exposure to anticoagulant rodenticides, including SGARs, as well as another subset of rodenticides: first generation anticoagulant rodenticides (FGARs).

Ironically, rodenticides can also be counterproductive to rodent control by poisoning and killing natural predators that help regulate rodent populations throughout California. One of the poisons developed as an FGAR is diphacinone, which is the most frequently detected FGAR in nontarget wildlife. For example, in a 16-year study of urban bobcats in Los Angeles, diphacinone was detected in approximately 30% of the blood samples tested. Exposure to diphacinone can result in both lethal and sublethal effects on nontarget wildlife, including severe skin diseases and decreased immune system response.

Numerous safer alternatives to SGARs and diphacinone are available. Exclusion, sanitation and physical controls are the most sustainable long-term rodent control solutions. Fertility control products have also proved effective and are now widely available. As of 2019, there were over 125 different rodenticide products registered for use in California that were not diphacinone or SGARs.

Given the ample evidence of harm caused by rodenticides like diphacinone, and the availability of effective alternatives, earlier this year I introduced AB 1322. The bill adds diphacinone to the existing rodenticide moratorium from AB 1788 to better protect wildlife from unintentional rodenticide poisoning while maintaining exceptions for its use to protect public health, water supplies and agriculture. It also requires that the Dept. of Pesticide Regulation enact stronger, permanent restrictions on SGARs and diphacinone to limit unintended wildlife poisonings.

California is one of the world’s 36 global biodiversity hotspots, due both to our wide variety of native plants and animals and high threat levels to that biodiversity. Rodenticides like FGARs and SGARs are among those threats and, thankfully, we can take action to limit their impact. That’s why passing AB 1322 is so important.

How do you feel about AB 1322? Please feel free to reach out to me with any comments, questions or concerns through my District Office at (818) 558-3043 or Assemblymember.Friedman@Assembly.ca.gov.