Avoiding and escaping predators: Movement tortuosity of snowshoe hares in risky habitats

Prey animals use different strategies to avoid detection by predators and to flee once detected. Key issues are what aspects of movement prey change in response to predation risk and how differences in habitat affect escape movements. We answer these questions for snowshoe hares (Lepus americanus) in Montana, using an experimental manipulation and habitats for which annual mortality rates varied more than fourfold. We examine a) whether the mortality risk of a habitat affects movement tortuosity and speed of foraging snowshoe hares and b) whether tortuosity and speed of hares fleeing from a predator (a leashed dog, Canis familiaris) differ among these forest stands. Snowshoe hares did not differ in tortuosity or speed while foraging in these stands, suggesting that other anti-predator behaviours were used. Hares fleeing from the leashed dog showed much faster and straighter movements than foraging hares, but escape trajectories were similar in all forest stands, suggesting a relatively inflexible response while fleeing. Varying tortuosity and speed are clearly part of the snowshoe hare's behavioural repertoire for escaping predation, but these attributes of movement were insensitive to the annual mortality rates in each forest stand.