Threshold concentrations of an anthraquinone-based repellent for Canada geese, red-winged blackbirds, and ring-necked pheasants

摘要

Wildlife repellents provide a non-lethal alternative for managing the monetary impacts of agricultural depredation. For the purpose of developing of an effective avian repellent, we established repellency thresholds of an anthraquinone-based repellent for Canada geese (Branta canadensis), red-winged blackbirds (Agelaius phoeniceus), and ring-necked pheasants (Phasianus colchicus) in captivity. We conducted a concentration-response experiment with Canada geese offered corn seeds treated with six concentrations of Avipelp repellent (a.i. 50% 9,10-anthraquinone). Based upon our laboratory efficacy data, we used non-linear regression to predict a threshold concentration of 1450ppm anthraquinone for geese offered treated corn seeds (i.e., 80% repellency; r po =0.85, P =0.009). We also observed a positive concentration-response relationship among red-winged blackbirds offered Avipelp-treated rice (r po =0.70, P =0.039) and sunflower seeds (r po =0.84, P =0.010). We predicted a threshold concentration of 1475ppm anthraquinone for blackbirds offered treated sunflower seeds. Blackbirds also reliably discriminated between untreated food and rice treated with 2325ppm anthraquinone (F , =3414.05, P <0.0001) or sunflower treated with 1778ppm anthraquinone (F , =175.39, P <0.0001). We observed a positive concentration-response relationship among ring-necked pheasants offered corn (r po =0.95, P =0.001) and sunflower seeds (r po =0.99, P <0.001) treated with Avipelp. We predicted a threshold concentration of 10,450ppm anthraquinone for pheasants offered treated corn seeds. Pheasants also reliably discriminated between untreated food and corn treated with 1900ppm anthraquinone (F , =919.86, P <0.0001) or hulled sunflower treated with 1140ppm anthraquinone (F , =177.35, P <0.0001). Avipelp seed treatments effectively conditioned avoidance of treated seeds among Canada geese, red-winged blackbirds, and ring-necked pheasants. Our laboratory efficacy data provide a reliable basis for planning future field applications of anthraquinone-based bird repellents for protection of agricultural crops, property, and related natural resources. Supplemental field efficacy studies are necessary for registration of anthraquinone-based repellents for managing agricultural depredation caused by wild birds.