Vegetative structure and composition determine snowshoe hare (Lepus americanus) activity at tree line

Background/Question/Methods

The snowshoe hare (Lepus americanus) is a keystone herbivore supporting many predators, including the Canada lynx (Lynx canadensis). By understanding the habitat use of snowshoe hare, we can predict their distribution and influence on predator populations, and how hares and their predators will be affected by disturbances, such as climate change. The objective of this study was to examine how snowshoe hare activity varied along tree line in Churchill, Manitoba. To estimate hare activity, we established six transects and counted fecal pellets at two plots per transect. We then estimated several habitat features surrounding the plots, including vegetation cover (horizontal percent cover), tree density, diameter at breast height (DBH), vertical cover (vertical percent cover of all vegetation types), and plant species abundance. 

Results/Conclusions

Snowshoe hare pellets occurred at a higher density where tall shrub cover was high and vertical cover was low. Variables such as canopy cover, DBH, tree density, and small shrub cover were positively correlated with pellet density, whereas herb cover and medium shrub cover were negatively correlated with pellet density. Snowshoe hares also preferred areas with willow cover, but avoided areas with black spruce cover. With climate warming, tree line is expected to advance northward, and shifts in plant abundance, structure, and composition might affect hare and predator dynamics.