Space use of an alpine ungulate during winter: The relative influence of snow cover and fresh snow

Background/Question/Methods

Winter brings a particular challenge for most animals in temperate climates. Snow is one of the most limiting environmental factors for wildlife during winter. Snow cover may limit space use, increase energetic expenditure related to movement, limit resource availability and ultimately affect individual survival. Most of the studies on the effect of snow on animal space use looked at the effect of snow cover or snow depth. The amount of fresh snow, however, could be more relevant for wildlife, especially in alpine or northern environments, where wind shifts and hardens the snow cover constantly. From 2011 to 2013, we studied space use of mountain goats (Oreamnos americanus) in relation to snow conditions within Jasper National Park in Alberta, Canada.

Results/Conclusions

During winter, daily movement decreased about eight times faster with the amount of fresh snow than snow cover. Weekly movements and range size decreased with the mean amount of snow fallen each day, but not with snow cover. When snow effects were accounted for, movement increased as winter advance, probably due to increases in day length. These results demonstrate the importance of taking freshly fallen snow into account in wildlife space use studies. Limited movement and range size of mountain goats highlight the energy saving tactic used in winter.