Karen E. Hodges

The University of British Columbia
Okanagan Campus


Conservation of peripheral populations

Fragmentation or degradation of habitats by human activity reduces the populations of many species, and indeed is one of the major causes of endangerment.  As species decline, they frequently are extirpated from parts of their range but retain reasonable populations elsewhere; recent evidence suggests peripheral populations are more likely to be retained. I am exploring ways of determining which peripheral populations are most valuable for conservation, and determining whether habitat fragmentation has the same impacts on populations at range edges as it does in range centers. Northern range edges also may be quite valuable as species expand ranges in response to climate change, but at present we lack good predictive tools for which peripheral populations will expand or contract under current stressors.

To address such questions, I am working in two primary systems. One is the snowshoe hare system, with study areas in fragmented and continuous study areas in various parts of the range. Snowshoe hares are thought to lose their population cycles in peripheral areas. Despite lots of speculation and theory, this pattern is not fully established nor is it known what mechanisms lead to altered dynamics. I am using field and modelling approaches in fragmented and unfragmented areas to examine how cyclicity changes with landscape patterns.

The second system is in the Okanagan region of British Columbia. The habitats represented here comprise some of the northernmost grasslands and sage-steppe ecosystems in the world, and for many species this region contains their northern range edge.  Recent projects include work on the federally threatened Great Basin Gophersnake, Great Basin pocket mice, western painted turtles, and the Nuttall's cottontail. 

In addition to wanting to understand the distribution and abundance of populations across these complex landscapes, I am also interested in assessing how individual animals use habitats and the movements they are willing to undertake. I and my students use tools like radio-telemetry, fluorescent powder, and snow-tracking as tools to address these behavioural questions.

More on habitat selection >>

Karen Hodges - Salish Mountains
This forested landscape in the Salish Mountains of NW
Montana has many different kinds of habitats in it,
resulting from fire and forestry activities.

Karen Hodges - 2003 East Fire 
The 2003 East Fire on the night it started in Yellowstone
National Park.  This fire burned several of our study areas in mature forest.

Karen Hodges - Burned Areas
All of these areas burned in the 1988 fires of Yellowstone. Fire severity and regeneration patterns are very different, with implications for how much different wildlife species use each area.

 Karen Hodges - Mature Stand


Last reviewed shim6/23/2017 4:37:15 PM