Restoring Wildlife Populations
I am interested in combining field data with population models and genetic analyses to help determine the most effective way to restore wildlife populations impacted by human perturbations. The modeling takes advantage of the sometimes surprising fact that all population processes (for example births and deaths of particular classes of individuals) are not created equal in their effects on population growth; by identifying that particular vital rates – say adult reproduction or juvenile survival – has disproportionate effects on population growth when modified under management, we can determine management strategies that are most likely to recover species that are hovering near extinction. We are doing this on a large scale by developing a general set of scientifically based rules for conserving and recovering rare and endangered species for which little data exist.
In the field, my graduate students and I have a number of restoration-related projects investigating factors that cause some wildlife populations to flourish while others decline toward extinction. One example includes our work with Olympic marmots, a distinct subspecies found only in and around Olympic National Park, Washington. We have been using non-invasive genetic sampling of marmots (using sticks with tape on them that grab the hairs of marmots as they emerge from burrows) and of coyotes (by collecting their feces and using genetic analysis to distinguish coyotes and determine their diet). From these studies we have learned that coyotes, recent colonizers of the Olympic high country only in the last couple of decades, are the most likely drivers of marmot decline.
Another wildlife restoration project includes nearly a decade of work my students, postdocs and I have been doing on snowshoe hare population dynamics. Hares are of inherent interest because of their famous cyclic dynamics in the North, and because they are the primary prey item for federally Threatened Canada lynx. The applied restoration components of these projects center on how hares respond to a variety of logging practices. Private timber companies (including Plum Creek) are now implementing new selective thinning regimes based on our field studies. Also, we are studying hares in Yellowstone and Glacier National Parks to understand the role that Parks play in maintaining and restoring hare and lynx populations.
Finally, we are linking ecological science to the recovery of particular threatened and endangered species. We are studying the federally Endangered Sierra Nevada bighorn sheep, the rarest mountain sheep in North America, across the handful of small and isolated subpopulations that make up the species distribution. By coupling years of field studies with GPS-based telemetry collars, genetic sampling, and habitat and population models, we aim to develop a scientific basis for recovering the species. Similarly, we are identifying the reasons that an endangered endemic flying fox in the Philippines is declining while a related species is increasing; by determining the causes for species differences we will be able to provide biological insights into recovery planning for the endangered flying fox.