Factors influencing killing rates of white-tailed deer by coyotes in eastern Canada

Predation affects the dynamics of many ungulate species. Until recently, little attention has been given to understanding the underlying processes and relationships in predator-prey systems. We examined factors affecting killing rates of white-tailed deer (Odocoileus virginianus) by coyotes (Canis latrans) in Nova Scotia, Canada. Snowshoe hare (Lepus americanus) and deer abundance. distribution and relative vulnerability of deer, and coyote group size all significantly influenced killing rates of deer by coyotes in winter. Groups of coyotes initiated proportionately more chases than single coyotes but chase success differed little among groups of 1-4 coyotes. Snow depth had a positive influence on success of pursuits. More kills were observed in areas of low deer density relative to areas with high deer densities. The mean distance of deer kills to recent clearcuts was significantly shorter than expected in an area where deer yarded during winter, but not in an area where deer did not aggregate during winter. Predator-prey ratios may not be a reliable indicator of predation rates of deer by coyotes because factors such as relative abundance and vulnerability of alternate prey, winter severity, and coyote social behavior also influence killing rates.