USDA National Wildlife Research Center Symposia


Date of this Version



Published in: Witmer, G. W., W. C. Pitt, and K. A. Fagerstone, editors. 2007. Managing vertebrate invasive species: proceedings of an international symposium. USDA/APHIS Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado, USA. Also available online at


Non-target species may be exposed to rodenticides via feeding on rodenticide baits or the carcasses of poisoned target species. As invasive species frequently negatively impact threatened or endangered (T and E) species, there is frequently spatial and temporal overlap of invasive species and T and E species. Risk assessments provide a means to estimate the probability of rodenticide associated adverse effects to non-target species (including T and E species). Quantification of risk provides critical information for decision-makers to weigh the benefits and risks of proposed rodenticide uses and to compare the risks of management with risks associated with no management (e.g. invasive species induced extinction of native species).