Variation in snowshoe hare density near Churchill, Manitoba estimated using pellet counts

Abstract

Snowshoe hares (Lepus americanus) are a keystone species in the Boreal Forest of Canada and their well-characterized population cycles can strongly influence the abundance of their predators. We examined annual variation in snowshoe hare density near Churchill, Manitoba, using counts of hare fecal pellets from 2012 to 2015. We used a regression formula to estimate the density of snowshoe hares based on fecal pellet density. Our estimates of snowshoe hare densities were highest in the first year of study, which may reflect a bias due to pellets accumulating from previous years, and we found no difference in hare density estimates in the subsequent three years. These results suggest the forest-tundra ecozone may be marginal habitat for snowshoe hares, precluding rapid increases in hare density, so population densities of snowshoe hares in Churchill may not cycle in their historic 10-year intervals. However, the northward advancement of the tree line with climate warming may improve habitat conditions for snowshoe hares, and thus the predator populations they typically support.