Antipredator strategies of caribou: dispersion along shorelines

Abstract

A small herd of 15–31 caribou (Rangifer tarandus) inhabited a shoreline strip of habitat along Lake Superior from 1972 to 1983. By remaining near the shoreline, they were spaced away from the major distributions of wolves (Canis lupus) and lynx (Lynx canadensis) that hunted mainly inland for moose (Alces alces) and snowshoe hares (Lepus americanus), respectively. Lake Superior also provided a means of escape from wolves, and offshore islands constituted safe parturition sites. The persistence of this herd is consistent with the hypothesis that viable caribou populations cannot survive on ranges frequented by high numbers of wolves (maintained mainly by moose prey) unless there are special habitat features providing escape for cows with young calves.