Proceedings of the Vertebrate Pest Conference

Rodenticides are an essential tool in the integrated pest management (IPM) of infestations of commensal rodents. With the introduction of Assembly Bill 2422 California Natural Predator Protection Act, the State of California is potentially facing a future with serious restrictions on the use of anticoagulant rodenticides to manage commensal rodents in urban areas. Assembly Bill 2422 has been proposed to protect predators from rodenticide poisoning and seeks to significantly restrict the application of first and second generation anticoagulant rodenticides for use in many urban and no-urban areas of California. Exclusion and cultural practices, such as landscape management and sanitation, are important and successful tools for managing rodent populations. However, quick and efficient control of commensal rodent infestations often necessitates the use of rodenticides. While rodenticide is an important tool, exposure of wildlife to anticoagulant rodenticides has been evident for many years in the state of California. When rodents are consumed by predators, second generation anticoagulant rodenticides can be detected as residues in the livers of predators. Many species of animals are documented as having succumbed to rodenticide toxicosis, however the effects of chronic, sub-lethal exposure to predators are not well understood. This paper will discuss the current and proposed changes to rodenticide legislation in California, impacts of the legislation on communities across California, and gaps in research preventing the adoption of evidence-based best management strategies for rodent control. In order to improve the success of commensal rodent control programs in California, effective strategies for rodent management must be developed.