New Maps Document Big-Game Migration Corridors Across Western U.S.

Nov 20, 2020

Wildlife managers across the West have a new tool when it comes to protecting iconic big game. A new report published by the U-S Geological Survey provides detailed maps of G-P-S tracked migration routes for mule deer, elk, pronghorn, moose and bison.

Report lead author Matthew Kauffman said stakeholders from conservationists to transportation agencies have long realized that it's critical to understand how big game move across Western landscapes.

"And are ready to roll up their sleeves and go to work to enhance and maintain the connectivity of these migration corridors. And now they have a tool that can guide that on-the-ground work," said Kauffman.

Development across the West, from energy production to expanding suburbs, has created roadblocks on routes used by wildlife for thousands of years. Kauffman said the new maps provide a blueprint for helping animals get back on track. Conservationists are hopeful the maps also can be used to monitor and limit the spread of contagious diseases, such as chronic wasting disease.

Kauffman said the research confirms that migration is how most animals earn their living in western states. Baby greens sprout up in lower elevations in early spring, and as temperatures rise, mule deer and other ungulates ride what Kauffman calls a green wave into higher elevations where their favorite food pops up next. Climate change also is impacting migration. Longer and more severe droughts has altered when and where food is available along historical corridors.

"Drought disrupts that green wave, and makes it more difficult for animals to surf. They still try, they do their best given the drought conditions, but they just can't be in the right place at the right time," said Kauffman.  

The new study builds on more than two decades of research by state wildlife agencies including G-P-S tracking-collar data, mapping more than 40 big-game migration routes in Arizona, Idaho, Nevada, Utah and Wyoming.