New Maps Document Big Game Migrations Across Western United States
Fellow map and big game junkies rejoice! The United States Geological Survey just released a really cool study that maps out some of the migration corridors used by big game animals in a handful of Western states.
For the first time, state and federal wildlife biologists have come together to map the migrations of ungulates – hooved mammals such as mule deer, elk, pronghorn, moose and bison – across America’s West. The maps will help land managers and conservationists pinpoint actions necessary to keep migration routes open and functional to sustain healthy big-game populations.
“This new detailed assessment of migration routes, timing and interaction of individual animals and herds has given us an insightful view of the critical factors necessary for protecting wildlife and our citizens,” said USGS Director Jim Reilly.
The new study, Ungulate Migrations of the Western United States: Volume 1, includes maps of more than 40 big-game migration routes in Arizona, Idaho, Nevada, Utah and Wyoming.
“I’m really proud of the team that worked across multiple agencies to transform millions of GPS locations into standardized migration maps,” said Matt Kauffman, lead author of the report and director of the USGS Wyoming Cooperative Fish and Wildlife Research Unit. “Many ungulate herds have been following the same paths across western landscapes since before the United States existed, so these maps are long overdue.”
The migration mapping effort was facilitated by Department of the Interior Secretary’s Order 3362, which has brought greater focus to the need to manage and conserve big-game migrations in the West. It builds on more than two decades of wildlife research enhanced by a technological revolution in GPS tracking collars. The research shows ungulates need to migrate in order to access the best food, which in the warmer months is in the mountains. They then need to retreat seasonally to lower elevations to escape the deep winter snow.
Big-game migrations have grown more difficult as expanding human populations alter habitats and constrain the ability of migrating animals to find the best forage. The herds must now contend with the increasing footprint of fences, roads, subdivisions, energy production and mineral development. Additionally, an increased frequency of droughts due to climate change has reduced the duration of the typical springtime foraging bonanza.
Fortunately, maps of migration habitat, seasonal ranges and stopovers are leading to better conservation of big-game herds in the face of all these changes. Detailed maps can help identify key infrastructure that affect migration patterns and allow conservation officials to work with private landowners to protect vital habitats and maintain the functionality of corridors.
The migration maps also help researchers monitor and limit the spread of contagious diseases, such as chronic wasting disease, which are becoming more prevalent in wild North American cervid populations such as deer, elk and moose.
To explore the Western Migrations web viewer, visit the online portal.