Concentration-response of an anthraquinone-based repellent for raccoons (Procyon lotor)

Abstract

Wildlife repellents can be part of non-lethal management strategies to reduce the negative impacts of wildlife to property, agricultural production, and human health and safety. Raccoons (Procyon lotor) are associated with negative impacts in all three of these areas. Anthraquinone is a useful avian repellent and its utility as a mammalian repellent is still being explored. Our objective was to evaluate laboratory efficacy of an anthraquinone-based repellent for raccoons using different concentrations. We fed captive raccoons whole corn treated at 0.5%, 1%, 1.5% and 2% anthraquinone and examined their behavioral response related to feeding repellency including consumption and change in duration related to approach, interaction and extended interaction with the feed bowl. Feeding repellency was 26–37% for whole corn treated with 0.5–1.5% anthraquinone and 71% for whole corn treated with 2% anthraquinone. Interaction duration among the treatments varied (p = 0.005) with a longer interaction duration with the food bowl at 2% anthraquinone compared to 0.5% anthraquinone. However, the addition of anthraquinone did not significantly alter behaviors of approach, interaction, or extended interaction between pretreatment and treatment for the raccoons within treatments. The decreases in consumption that we observed warrant development of further research and field evaluation regarding anthraquinone as a deterrent with raccoons or to repel vertebrate competitors from raccoon specific baits.