title: Capsicum-laden soils decrease contact time by northern pocket gophers.
abstract: Fossorial rodents damage lawns/water impoundments/crops. We conducted a two-choice, parametric-type study to determine the effects of capsicum-oleoresin/soil mixtures (0.00, 0.75, 1.50, and 2.25%) upon soil-contact, soil-digging, and pelage-grooming behaviors in northern pocket gophers (Thomomys talpoides). In 3 alternate-day (1-h/day) exposures to > or = 1.50% capsicum-oleoresin soil mixtures, gophers decreased mean soil contact time by 46% relative to placebo-exposed animals. Grooming time yielded a concentration x trial interaction that showed intense grooming by capsicum-exposed animals during trial 1, with "convergence" of times to near those of the "placebos" (0.00% capsicum oleoresin) by trial 3. The significant decrease in grooming activity was attributed to the gophers' reduced contact with capsicum soil across repeated exposures, rather than to chemical habituation. Soil-digging behaviors were minimally affected. Results demonstrate the feasibility of deterring gopher habitation by mixing chemical irritants in soil.
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, National Wildlife Research Center, Fort Collins, CO 80521-2154, USA. ray.t.sterner@usda.gov
authors.forename: R T
authors.initials: RT
authors.lastname: Sterner
authors.forename: K A
authors.initials: KA
authors.lastname: Hollenbeck
authors.forename: S A
authors.initials: SA
authors.lastname: Shumake
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects; D001362:Avoidance Learning / Q000187:drug effects*; D002211:Capsaicin; D005260:Female; D006120:Grooming / Q000187:drug effects; D007509:Irritants; D008297:Male; D010571:Pest Control / Q000379:methods*; D012377:Rodentia / Q000523:psychology*; D012987:Soil; D013997:Time Factors
chemical_list: D007509:Irritants; D012987:Soil; D002211:Capsaicin