Prey switching and feeding habits of eastern coyotes in relation to snowshoe hare and white-tailed deer densities

We investigated the influence of white-tailed deer (Odocoileus virginianus) and snowshoe hare (Lepus americanus) availability on the feeding habits of coyotes (Canis latrans) in Nova Scotia from 1992 to 1997. We hypothesized that coyotes would switch from deer to hare as hare abundance increased. Based on the analysis of 2443 scats, deer and hare were the dominant food items. Other important food items included small mammals, and fruits during late summer. In areas where they were readily available, coyotes fed predominantly on hare during winter, with the use of deer declining as hare density increased. However, the functional response was not proportional to the changes in the relative densities of deer or hare. This was particularly evident at low deer densities, where coyotes continued to feed largely on deer, even in the presence of high hare densities. The consumption of deer fawns during June and July exceeded that of hare in all areas, despite high hare densities in some areas. Overall, high use of deer appeared to have been associated with increased vulnerability due to winter severity or, in the case of young fawns, inability to escape. During mild winters, we suspect that coyotes are forced to focus their hunting efforts on prey other than deer, regardless of density, owing to low vulnerability of deer. When severe winter conditions occur, coyotes switch to feeding mainly on deer.