Ecology and Vulnerability

Snowshoe Hare

Background
The snowshoe hare is a cold-adapted species that ranges from the northern Canadian Arctic and extends south along the Sierra Nevada, Appalachian, and Rocky mountain ranges¹.  In eastern North America, the range extends to just south of New England, although along the Appalachian Mountains snowshoe hares can be found as far south as North Carolina and Tennessee². The snowshoe hare is often found in boreal and subalpine forests, although it uses a variety of other habitats including aspen parkland, mixed deciduous forest, coniferous forest, commercial tree plantations, orchards, and shrub areas^1,2. 

Climate Impacts
Climate change is expected to shift the ranges of boreal species, such as the snowshoe hare, northward. Given Massachusetts’ location at the southern edge of the species’ range, it seems unlikely that a warming climate will be favorable to snowshoe hare populations in the state. Fragmentation and loss of southern populations of hares are anticipated³. 

In addition, snowshoe hares exhibit seasonal changes to coat color that help them to evade detection by predators, such as coyotes, foxes, hawks and owls.  In summer, their fur is grayish- to reddish-brown, while in winter it is almost pure white for camouflage in the snow².  Timing of molting shows limited response to snow conditions within a given location but appears instead to be fixed by photoperiod⁴.  This indicates that as the number of days with snowcover declines due to climate change, snowshoe hares will experience longer mismatches between coat color and ground cover, leading to increased vulnerability to predators^4,5.  Hares do not appear to recognize this mismatch as they show no behavioral changes when their coat color does not match ground cover⁴.  Because plasticity is limited, the ability of snowshoe hares to respond to climate change will require natural selection on coat phenology (timing) or behavior^4,5.