About This Project

Anticoagulant rodenticides (AR) exposure is pervasive in carnivores, with direct and indirect effects on survival. Bobcats in Southern California are more likely to die from mange following AR exposure. While prohibitive legislation has recently been passed, a complete ban to prevent further wildlife poisoning requires demonstrating causality. We will combine advanced molecular methods with a non-invasive exposure assay to demonstrate the causal link between mange and AR exposure in bobcats.

Ask the Scientists

What is the context of this research?

Previous research by the National Park Service and our lab has linked anticoagulant rodenticide (AR) exposure to increased mange susceptibility in bobcats of the Santa Monica Mountains. A series of immunological assays showed that exposure to ARs causes severe dysregulation of the immune system, disabling the bobcats ability to generate a targeted immune response against the mange pathogen. However, the underlying molecular pathways causing this immune dysregulation are not understood and may be necessary to demonstrate a direct causal link between AR exposure and population health. This demonstration will provide stronger support for the need to eliminate all use of ARs for rodent control. We want to keep our wildlife (and our pets) safe!

What is the significance of this project?

Recently, the California Department of Pesticide Regulation reviewed the safety of ARs for the environment and passed regulations to limit but not eliminate their use. We feel strongly that even with limited use, these compounds will reach and effect non-target wildlife up the food chain. We are working to provide regulatory agencies with direct evidence that these compounds are unsafe for use in any context and should be eliminated.

What are the goals of the project?

We have already conducted gene expression analysis on 53 wild-captured bobcats for which ARs were and were not detected in whole blood. Our results are promising and we are identifying several gene pathways that play a role in immune dysregulation.

This summer, we plan to sample 6 captive animals that we know are not exposed to ARs. We have a non-invasive assay using a small amount of whole blood in which we can introduce specific stimulants to the assay vial and evaluate gene expression differences from the same individual. We will assay each animal for its response to a single AR, the mite antigen and an AR plus the mite antigen. This will enable us to demonstrate the causal link needed to facilitate further review by pesticide regulatory agencies.