Numerical and functional responses of wolves, and regulation of moose in the Yukon

摘要: Numerical and functional responses of wolves (Canis lupus) were studied in a 23,000 km2 area the east-central Yukon. Populations wolf, moose (Alces alces) woodland caribou (Rangifer tarandus caribou) increasing following intensive reduction wolf numbers. Snow-tracking surveys radiotelemetry studies indicate that population recovered to pre-reduction densities within 4 years. The was colonized initially by young dispersed into vacant territories, packs shlfted from boundaries study area. Survival rates highest reported published literature. Pack splitting became more common as size increased. Dispersal positively correlated densities. Wolf numerical response appeared be tightly regulated ungulate supply. Two hundred ninety-one moose, 30 1 mountain sheep (Ovis dalli) found dead during my study. Wolves killed mainly old most prey not nutritionally stressed. predation additive mortality both populations. Killing 2 different 45 periods late winter. Kill rate negatively with pack but density, searching rate, snow depth, observation rates, wolfiprey ratios, availability alternate prey, or snowshoe hare abundance. Also, kill calves size, depth calf each small had disproportionately higher on compared large packs. Predation main factor limiting recruitment caribou, survival adult moose. density-independent when between 0.25 0.43 moose/km2. At lower densities, decelerating type I1 best fit data, I could determine if it is regulatory anti-regulatory combine data other show regulate single low density equilibrium (0.12 moose/km2> wolf: systems North America. My model indicates bear changes habitat quality have little effect stable point, where are primary wolves. also no unstable upper boundary exists beyond which escape regulating predation. Wildlife managers should expect permanent benefits for temporary programs relatively simple systems.