An Assessment of Coyote and Dog Predation on Sheep in Southern Iowa

Abstract

A questionnaire survey, field necropsies, domestic-animal claims, and a postcard survey were used to assess coyote and dog predation on sheep in southern Iowa. Forty-one percent of 1,251 questionnaire respondents reported they had sheep killed by dogs or coyotes (Canis latrans) during 1975. Of the total losses reported, 41% were attributed to predation, 30% to disease, and 13% to unknown causes. Three percent of all sheep owned by the questionnaire respondents allegedly were killed by coyotes, and 1% were killed by dogs. Both field necropsies and domestic animal claims showed that dogs killed more sheep per incident and sheep per operator than did coyotes. Almost 60% of the postcard respondents attributed sheep losses to predation during 1976 and 1977. Coyote predation varied during summer and fall, with 80% of the incidents occurring from 1 May to 1 October; dog predation did not follow a distinct chronological pattern. Field necropsies of 227 alleged predator-caused sheep losses revealed that sheep producers correctly assessed the cause more than 94% of the time. The results of the questionnaire and postcard surveys were similar. Domestic-animal claims underestimated the actual number of losses that occurred. J. WILDL. MANAGE. 45(4):883-893 Intensive predator control measures implemented by early settlers drastically reduced the number of coyotes in Iowa (Van Hyning and Pellett 1910, Scott 1937, Bowles 1975). During the past 20 years, however, the coyote population in Iowa and the incidence of reports of livestock losses due to coyote predation have increased considerably (Boggess 1975, Bowles 1975, Andrews and Boggess 1978). Concurrently, fur prices have increased dramatically (Andrews and Boggess 1978), making the coyote an important resource for hunters and trappers. Boggess et al. (1978) found that, since 1970, alleged sheep losses caused by dog predation have decreased at about the same rate that losses due to coyote predation have increased. This suggests that coyotes may be blamed for some losses actually caused by dogs (Denney 1974). Recent field studies (Henne 1975; McAdoo 1975; DeLorenzo and Howard, unpubl. rep., U.S. Fish and Wildl. Serv., Denver, Colo., 1976; Nesse et al. 1976; Nass 1977; Tigner and Larson 1977) and surveys (Nielson and Curle 1970; Reynolds and Gustad, unpubl. rep., U.S. Fish and Wildl. Serv., Denver, Colo., 1971; Early et al. 1974; Meduna and Robel, unpubl. data, 1976; Nesse et al. 1976; Gee et al. 1977) have explored the impact of coyote predation on the sheep industry in western states. However, similar research has been needed in the midwestern farm states, where livestock husbandry practices, habitat, dog and coyote densities, and predator control methods are quite different from those in the West. Before implementation of a management plan for the coyote in Iowa, the extent of sheep losses and the factors influencing losses caused by coyotes and dogs needed to be assessed. We are grateful to all who assisted in this project. H. Bal, R. Bishop, R. Coffey, W. Downing, A. Farris, W. Franklin, J. Heer, E. Johnson, E. Klaas, M. Ryan, R. 1 Joint contribution: Iowa Conservation Commission Federal Aid to Wildlife Restoration Project W115-R-4 and 5, and Journal Paper J-9778 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project 2031. J. Wildl. Manage. 45(4):1981 883 This content downloaded from 157.55.39.159 on Sun, 18 Sep 2016 06:02:57 UTC All use subject to http://about.jstor.org/terms 884 COYOTE AND DOG PREDATION ON SHEEP* Schaefer et al. Schaefer, C. Steffen, T. Wickersham, L. Wing, and A. Wywialowski provided valuable criticism throughout the study and preparation of the manuscript. J. Prescott, C. Roberg, and R. Sayles assisted in data coding, and H. Cook, J. Kienzler, and V. Wright were extremely helpful with the questionnaire design and data analysis. We also thank the coyote hunters, trappers, and sheep producers in southern Iowa for their cooperation.