Before all the snow melted last week, I went snowshoeing at the Great Works Regional Land Trust’s Rocky Hills Preserve in South Berwick. It was that day with close to zero temperatures. Not much was stirring in the woods but tracks in the fluffy snow were evidence of squirrels, fox, deer and snowshoe hare. While I see squirrels and deer on a regular basis, and foxes occasionally, I have yet to see an actual snowshoe hare, but I know they are here because in the winter I find their tracks.
According to NH Fish and Game, snowshoe hare are found throughout New England, across Canada, and south to the Appalachian and Rocky Mountains. In New Hampshire and Maine they are most abundant in the northern three counties. I like finding them down here near the coast because, to me, as a northophile, I love anything reminiscent of the North. Snowshoe hares are that - they are residents of the great boreal forests, superbly adapted to winter’s snow.
In addition to snowshoe hares, in New England we have two types of cottontail rabbit, the New England cottontail (endangered or very rare in most places), and Eastern cottontail (non-native north of the Hudson River, introduced in the early 1900s and now abundant). Hares differ from rabbits in many ways, the most obvious being that hares are larger with, generally, longer legs and ears than rabbits. The two most distinguishing characteristics of the snowshoe hare are the snowshoe-proportioned, densely-furred hind feet that give snowshoe hares excellent buoyancy in soft, deep snow, and their variable coats that turn white in the winter and reddish-brown in the summer for camouflage. For this reason, another common name for the snowshoe hare is the "varying hare.”
In winter, it is almost impossible to mistake the track of a snowshoe hare for that of a cottontail. The sheer size of the hind foot is a good clue. Eastern cottontail hind feet are generally a puny 3 inches long, while snowshoe hare hind feet can reach almost 6 inches in length.
Right now, in between snowstorms might be the best time to look for actual snowshoe hares - they should all be white, perfect for blending in with the snow but guaranteed to stand out against the brown landscape. There has been quite a bit of recent research into whether and how non-hibernating animals that change color in winter (ermines are another mammal that does this that lives around here as do arctic foxes and arctic hares up north), will adapt to the changing climate. For snowshoe hares, a mismatch at the start and end of winter has been observed - hares molt to white before the snow settles in and don’t lose their winter coats until well after the new, and earlier, spring thaw. These animals are now easy targets for predators. What can they do? Snowshoe hares cannot control when they change color - the timing of that change is dictated by day length.
A recent study that compared snowshoe hares in Pennsylvania to a population in the Yukon found that the Pennsylvania hares are compensating for shorter periods of snow in winter by seeking shelter that offers visual obstruction from predators more often than their northern counterparts who sought shelter primarily for warmth (Canadian Journal of Zoology, 2017, Vol. 95, No. 8 : pp. 539-545 “Geographic variation in winter adaptations of snowshoe hares,” by L.C. Gigliotti, D.R. Diefenbach, M.J. Sheriff ). This is a behavioral change, a good first step, but they still will have difficulty foraging - a time when they have to venture away from cover.
There might also be some genetic change as well. This same study found a small number of Pennsylvanian snowshoe hares that did not molt at all, they stayed brown all year. Since, individual hares have no control over molting, this kind of change must be taking place at the genetic level. The snowshoe hare population must have enough variability in offspring that the couple babies who didn’t molt to white and in the past stood out in winter and were subsequently killed by predators, now have a competitive edge and survive. This is the race that many animals are now in - can they adapt fast enough to survive a rapidly changing climate?
Susan Pike, a researcher and an environmental sciences and biology teacher at St. Thomas Aquinas High School, welcomes your ideas for future column topics. She may be reached at spike3116@gmail.com. Read more of her Nature News columns online.