Date of this Version
Young, J.K., M.J. MacGregor, E.N. Gese, and D.C. Eckery. 2018. Experimental tests of nonsurgical reproductive inhibitors to prevent coyote reproduction. Human-Wildlife Interactions 12(2):171-185. https://digitalcommons.usu.edu/hwi/vol12/iss2
Sterilization is an effective nonlethal tool to reduce livestock depredation by coyotes (Canis latrans) because adults without pups to provision are less likely to kill livestock. Surgical sterilization is costly and invasive, so identifying nonsurgical methods for canids that allow wide-scale application is important. We conducted a preliminary assessment of 2 types of reproductive inhibitors (gonadotropin releasing hormone [GnRH] vaccine and deslorelin, a GnRH agonist) on coyote reproductive capabilities. We treated captive coyotes with a GnRH vaccine (n = 6 males, n = 6 females) or deslorelin (n = 6 males), measured number of litters and pups born, and compared their behavior and hormone levels to captive coyote pairs in which the male was surgically vasectomized (n = 6). At least half of the pairs receiving treatment with either of the nonsurgical reproductive inhibitors produced pups, and litter size was larger than expected compared to historical records. Male coyotes treated with deslorelin showed decreased testosterone levels, whereas there was no difference in testosterone levels in males treated with GnRH vaccine compared to controls. Behavior did not differ between any groups. Despite the lack of efficacy of either reproductive inhibitor tested, our research suggests that hormonal alterations that disrupt reproduction of coyotes are unlikely to negatively affect behavior, and further investigation of nonsurgical reproductive inhibitors for wild canids is warranted.