POPULATION-DYNAMICS OF COYOTES IN CENTRAL ALBERTA, 1964-1968

Coyote (Canis latrans) populations and ecology were studied in a mixed farming-boreal forest ecosystem in central Alberta [Canada]. Carrion provided 1/2 of the coyotes'' food and was especially important in winter; mice were next in importance and their use peaked in summer and autumn. Use of microtines was directly correlated to their abundance. Density of coyotes was estimated at between 6 and 40, 9 and 60, and 4 and 27/100 km2 in winters 1965-66, 1966-67 and 1967-68, respectively. A major decline in coyote density from 1964-1965 was suggested by livetrapping data; probable causes were low microtine and snowshoe hare (Lepus americanus) populations in summer 1965 and an outbreak of mange. Age at marking affected both frequency of relocation and distance moved by coyotes; distance moved also was related to sex but not to number of relocations. Juveniles were more mobile than adults and young females were more mobile than young males. Dispersal started in Oct. and was random in direction. Sex ratios did not differ from 50:50. Pregnancy rates were 94% for adults and 14% for yearlings with corresponding placental scar counts of 6.0 and 5.2/female. Litters at dens (26) averaged 5.3 pups, and 3 of 29 dens held 2 litters each. Recovery rate of pups marked at dens was 20% and of non-pups, 41%. Mortality rates estimated from recoveries of marked animals were 71% for age 0-1 yr and 36-42% for coyotes over 1 yr old.