Dr. Karen E. Hodges  Professor, Conservation Ecology

Population Dynamics

Snowshoe hares: impacts of fragmentation and isolation on population dynamics of a keystone forest herbivore

Snowshoe hares, Lepus americanus, have a 10 year population cycle, which affects many other species in the boreal and montane forests of North America; they are a keystone herbivore.  I am interested in understanding the causes of the cycle, variation in the cycle across space and time, habitat factors contributing to regional densities and dynamics of hares, and synchrony of snowshoe hare populations across a range of habitat types and locations. Canada lynx, Lynx canadensis, are listed as threatened in the contiguous US. Lynx are a specialist predator on snowshoe hares, but lynx populations in the US have declined over the last several decades.  Habitat loss (via development, fire, and forestry activities) is one possible cause for lynx declines, especially as fragmented landscapes appear to support fewer hares.

I have been collaborating with other academics and people from state / provincial and federal agencies on these questions.  Our work has involved research areas in Montana (two national forests and Glacier National Park), Wyoming (Yellowstone National Park), the North Cascades of Washington (Okanogan National Forest), and southern and central British Columbia. In each area, habitat quality varies significantly for snowshoe hares, as well as the landscape context surrounding individual high-quality patches. Some areas have relatively large areas of suitable to high-quality hare habitat, whereas others are heavily fragmented by fire or by forestry activities and have areas that are essentially unsuitable for hares. We are obtaining demographic and genetic information to address how habitat quality and landscape patterns affect movements, population dynamics, and synchrony among hare populations.  We are also using several modelling approaches to enrich our understanding in these areas.

Snowshoe hares also offer a number of opportunities for behavioural work, and I have enjoyed using information from tracking, browse, radio-collars, etc. to understand how hares navigate complex habitats and landscapes.