Tests for Olfactory Repellents for Coyotes and Dogs

Abstract

Five coyotes (Canis latrans) and 3 dogs were individually trained to run from a start box across a 6,400-m12 enclosure to a visual stimulus where they received a food reward. Candidate repellents were presented in the area of the visual stimulus, and their ability to inhibit the test animal's food-getting response was measured. Of the 45 candidate repellents tested, only p-chloro-acetyl chloride repelled all of the test animals; however, it is a strong irritant and lachrymator and would be impractical for use in close proximity to sheep. Cinnamaldehyde showed some promise as a repellent. However, no chemical odor was found that consistently would repel coyotes and dogs but not adversely affect sheep. J. WILDL. MANAGE. 40(7):145-150 Coyote predation on domestic sheep has been a controversial topic for several decades. Assessment of losses caused by coyotes has been difficult (Shelton 1973, Wagner 1972). Furthermore, disagreement exists on the proper methods and extent of control measures (Cain et al. 1972:111, Noh 1973, Statement to the Subcommittee on Fisheries and Wildlife Conservation and the Environment, of the Committee on Merchant Marine and Fisheries, March 20), as well as which agency should have the responsibility for control (Howard 1974). Another point of discord is whether lethal prophylactic methods used to reduce coyote densities are effective in reducing sheep losses. The Cain Report (Cain et al. 1972: 49) showed a correlation between coyote densities and sheep losses. However, Wagner and Pattison (1973) reanalyzed the data and reversed Wagner's (1972:54) earlier statement that reduction in coyote numbers does not appear to reduce total sheep losses materially... . The economic (Balser 1974) and long range ecological effects of prophylactic methods are other factors that need careful investigation. Not all coyotes actively prey upon sheep. Both the Leopold Report (Leopold 1964) and the Cain Report (Cain et al. 1972:111) emphasized a need to focus control efforts on offending coyotes. These reports further encouraged research on selective non-lethal methods, including repellents. Increased impetus for research in this area was provided by Executive Order No. 11643, which prohibited the use of chemical toxicants on federal lands except under emergency conditions. Two recent studies tested methodologies to be directed at offending coyotes. These involved aversive conditioning with electric shock (Linhart et al., unpublished data) and lithium chloride, an emetic (Gustavson et al. 1974). This paper is a report on research to find or develop a natural or synthetic odor that will repel coyotes and dogs. This research was part of an interdepartmental project at Colorado State University involving the efforts of numerous individuals. Of particular assistance were C. D. Jansen, D. A. Wade, and G. J. Wolfe, Department of Fishery and Wildlife Biology; D. A. Cramer, 1 Financial support for this research was provided by Cooperative Agreement 12-14-100-11, 212(44) with the Agricultural Research Service, USDA. A graduate research scholarship was provided by the Rob and Bessie Welder Wildlife Foundation. 2Present address: Box 298, Wilson, Wyoming 83014. J. Wildl. Manage. 40(1):1976 145 This content downloaded from 157.55.39.30 on Wed, 20 Jul 2016 06:04:19 UTC All use subject to http://about.jstor.org/terms 146 OLFACTORY REPELLENTS FOR COYOTES * Lehner et al. Table 1. Test animals and results of baseline trials (10 trials/animal). Mean Agea time Animal Sex (yr) (sec) SD