Wildlife Damage Management, Internet Center for


Date of this Version

October 2000


Sterner (In press) described the use of a priori, theoretical analyses of crop/resource savings and benefit:cost ratios as a way of making intervention decisions in wildlife damage management. Iterative (1-variable-changed-at-a-time) calculations of these economic indices were computed for the use of zinc phosphide baits to control vole {Microtus spp.) populations in alfalfa (Medicago sativa). Results showed that indices displayed transitive effects — greater net savings and benefit:cost ratios were related to larger field-size, crop-damage and bait-effectiveness variables, but smaller bait-application fees. Ratios varied between 0.40 and 6.45, with -5-10% vole-caused damage required to produce returns on investments equal to the costs of control (benefit:cost ratio = 1.0). This paper presents the detailed Lotus® 1-2-3®, 9.5 code used to derive the results of Sterner (In press). Adaptation of the code to the study of other wildlife damage management problems is straightforward.