Field Trials Of Pocket Gopher Control With Cholecalciferol

Cholecaliferol (Vitamin D-3) was evaluated as a field rodenticide for controlling pocket gophers (Thomomys spp.) under forest and seed orchard conditions by monitoring radio-equipped pocket gophers following the application of 0.0%, 0.003%, 0.04%, 0.075% and 0.15% cholecalciferol oat baits. Tn one trial, the difference in mortality of the three lower concentrations was not significantly greater than the control group. In two subsequent trials with the higher concentration (0.15%), mortality between the treatments was significantly greater than in the control groups. We recommend that primary and secondary hazards of cholecaliferol to nontarget species and predators be investigated.