Demographic and dietary comparisons of forest and farmland Coyote, Canis latrans, populations in Alberta

Todd, Arlen W. 1985.Demographic and dietary comparisons of forest and farmland Coyote, Canis latrans, populations in Alberta.Canadian Field-Naturalist 99(2): 163-171.Demographic and dietary comparisons of Coyotes, Canis /atrans, in forest (> 50% forest cover) and adjoining agricultural (> 50% cleared) habitats of Alberta were made during 1972-75 by examining 1038 carcasses obtained from trappers, hunters, and other sources.During this period, Coyote populations in the forest declined about 2-4 fold in response to a continuing cyclic decline of Snowshoe Hares, Lepus americanus (from intermediate to scarce levels of abundance), whereas farmland Coyote populations evidently did not.Farm carrion was the single most important winter food of Coyotes in both forest and farmlands (33 and 61% volume in stomachs, respectively), although its availability was evidently limited in the forest.Use of Snowshoe Hares declined with hare abundance in both habitats; alternate foods were apparently not adequate during hare scarcity in the forest as rates of total food consumption by forest coyotes appeared to decline.Body-fat indices were generally lower, and overwinter fat losses generally greater, for forest coyotes.Pregnancy rates varied more between years in forest habitats and were lower (P = 0.06) among adults than in agricultural habitats (63% vs. 86%).The proportion of juvenile Coyotes declined in the forest (P< 0.001) after 1972-73, once hares became scarce, but not in agricultural habitat.Sex ratios of Coyotes favored males in the forest when hares were at intermediate levels (P< 0.05), but were balanced otherwise.Relative stability in numbers, physical condition, breeding rates and age and sex structure in agricultural compared to forest habitats is attributed to more favorable environmental conditions for Coyotes in the former.