Date of this Version
Applied Animal Behaviour Science 185 (2016) 95–102
Effective chemical repellents and repellent application strategies are needed to manage damages caused by wild rodents and rabbits to agricultural resources. For the purpose of comparatively investigating the behavioral response of wild rodents and rabbits to a chemical repellent, we experimentally evaluated the concentration-response relationship of an anthraquinone-based repellent in California voles (Microtus californicus Peale), Richardson’s ground squirrels (Urocitellus richardsonii Sabine), deer mice (Peromyscus maniculatus Wagner) and cottontail rabbits (Sylvilagus audubonii Baird) in captivity. We observed 52–56% feeding repellency for whole oats treated with 10,800ppm anthraquinone or 18,500ppmanthraquinone in mice and squirrels, and 84–85% repellency for oats treated with 18,300ppm anthraquinone or 19,600ppm anthraquinone in voles and rabbits, respectively. In addition to providing the negative postingestive consequences necessary for conditioned food avoidance, the anthraquinonebased repellent also absorbs ultraviolet (UV) wavelengths that are visible to most wild birds. For the purpose of developing a repellent application strategy to modify the behavior of vertebrate pests, we therefore conducted a conditioned avoidance experiment by offering repellent- and UV-treated food to California voles in a subsequent behavioral assay. Relative to unconditioned test subjects (P = 0.3161), voles conditioned with the UV, postingestive repellent subsequently avoided whole oats treated only with an UV cue (P = 0.0109). These behavioral responses to anthraquinone-based repellents and UV feeding cues can be exploited as a repellent application strategy for wild mammals. We discuss potential applications of preplant seed treatments and surface treatments that include postingestive repellents and related visual cues for the protection of agricultural resources associated with mammalian depredation.