A 3-Year Evaluation of Taste Aversion Coyote Control in Saskatchewan

Abstract

Taste aversion programs using lithium chloride (LiCl) in sheep baits and carcasses have been applied in Washington to one sheep herd for 2 years; applications have been made in California and in Saskatchewan on 46 herds over 3 years. Ten of these 46 herds were available for statistical analysis, indicating a significant reduction in the percent of sheep lost to coyotes. All applications have suggested reduced sheep losses to coyotes (Canis latrans). This method of predation control may cost less than traditional techniques, save sheep, and should allow coyotes to carry out positive functions in the ecosystem. Our purpose has been to alter the predatory behavior of coyotes (Cunis lotruns) in “natural” settings to reduce sheep losses. Our working model (Gustavson et. 1979) was based on experimental evidence from rats in the laboratory. Data from most field settings remain indicative, and subjective, even when precautions are taken. Laboratory findings involve objectively measured, discrete responses in controlled settings. Laboratory studies have a high degree of control resulting in internal validity but may lack the external validity needed for generalization to the field. We conducted laboratory studies (Gustavson et al. 1974; Gustavson et al. 1976) under varied conditions to improve external validity while maintaining confidence in our conclusions. Several field investigations have been conducted with primary applications being made by researchers, (Gustavson, et al. 1976; Ellins et al. 1977; Stream 1976).