Effects of climate change on winter snowshoe hare (Lepus americanus) populations in New Brunswick
University of New Brunswick
Climate change has led to a decrease in the amount of snow cover on the ground in southern New Brunswick and is predicted to impact snowshoe hare, a species that moults to white pelage each winter, and thus becomes vulnerable to predation if living on snow free ground. I studied the relationship between winter snow cover variables and the number of snowshoe hare tracks along provincial government snow stations in New Brunswick, from 1963 to 2022. Using national weather station and provincial government data, I assessed five snow variables in each of the north, central, and south zones of New Brunswick and compared trends to changes in the number of snowshoe hare tracks. Since 1963, snow conditions in the central and north zones are deteriorating, but the change is less severe compared to changes in the south zone. The number of days with no snow on the ground in the south zone of New Brunswick has increased, from 107.6 days in the early 1960s to as much as 117.5 days between November 1 and May 31, in some years. Although the number of hare tracks have declined, the decline has also occurred in the northern zone, which does not support my prediction. The hare track data may not be sensitive enough to detect change but it is more likely that enough snow still remains to support snowshoe hare populations. However, at some point in the future, I predict that a threshold in the number of days without snow will be surpassed and the decreasing snow will eventually result in unsustainable mortality rates for snowshoe hare in the southern zone of New Brunswick.