Relative palatability and efficacy of brodifacoum-25D conservation rodenticide pellets for mouse eradication on Midway Atoll

Abstract Invasive mice ( Mus spp.) can negatively impact island species and ecosystems. Because fewer rodent eradications have been attempted for compared to rats Rattus spp.), less is known about efficacy palatability of rodenticide baits mouse eradications. We performed a series bait acceptance cage trials using standard formulation brodifacoum-based on wild-caught from Sand Island, Midway Atoll, help inform proposed eradication there. Mice were offered ad libitum brodifacoum pellets along with various alternative food sources, “no choice” treatment group received only pellets. Mortality in the no choice trial was 100%; however, when foods, preferred diets bait, leading low mortality (40%). there concern that bittering agent Bitrex® may reduced palatability, we conducted subsequent comparing without Bitrex. with-Bitrex slightly higher, indicating not likely responsible efficacy. Laboratory cannot account numerous environmental behavioral factors influence nor replicate true availability sources environment, so results these should be interpreted cautiously necessarily as measure likelihood success or failure eradication.