Connectivity 101- Least Cost Path Modeling for Lynx

This article is the 2nd in a series of posts on connectivity. The series will touch on wildlife connectivity projects that will be presented on at the upcoming Joint USGS and Society for Conservation Biology Conference in Flagstaff, AZ in October 2009.

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In 1999, Canada Lynx were re-introduced in Colorado. Here, the southern rockies make up the southernmost part of their geographic range. While lynx historically ranged up and down the the Rockies, their numbers began to dwindle after the west was won. They were extirpated from Colorado by 1973 -likely due to trapping and poisoning.

Lynx are a wide-ranging mammal that occurs in fairly low densities, relative to, say, bunnies. Lynx have evolved as a well equipped predator, specializing in hunting the snowshoe hare.

Photo caption: Lynx released in the San Juans of Southern Colorado, like the one in this 2006 file photo at New West, are making their way north and running into some barriers at Vail Pass. Photo by Bob Berwyn.

Lynx populations require connectivity across a broad geographic range in order to ensure gene flow, allow for long-distance dispersals, and keep populations from becoming isolated. To date, the lynx populations in the northern and southern rockies are isolated from one another by the "Berlin Wall for wildlife in the Southern Rockies"- which includes Vail Pass and Interstate 70.

One of the speakers for the upcoming conference (Allison Jones) is going to present on a project she worked on- modeling potential regional-scale travel corridors between core patches of lynx habitat in the southern and northern Rockies.

Scientists at the Wild Utah Project, or WUP, delineated landscape routes offering the best chance of success for Canada lynx moving among large “core patches” of habitat in the Utah-Wyoming Rocky Mountains Ecoregion south of Yellowstone to the San Juan Mountains in Colorado. These are commonly referred to as "corridors", or sometimes "linkages."

They modeled habitat suitability and configured the results to identify potential core habitat areas for lynx. They modeled cost surfaces of movement between the core patches based on vegetation type, road density, housing density and slope and identified a least-cost corridor to locate broad potential corridor routes between core patches.

The resulting corridors may be targeted as priority areas for wildlife managers to conserve in order to improve connectivity for lynx between the northern and southern Rockies.