Using the latest technologies involving GPS-enabled collars, wildlife biologists can track big game migrations in real time as animals move—in some cases—hundreds of miles. With this data, researchers are then able to analyze the effects of development, roads, and climatic conditions on animals’ historic migration routes, which can help state and federal agencies make informed wildlife management and development decisions.
Matthew Kauffman, Ph.D., a researcher for the United States Geological Survey (USGS) and the lead scientist for the Wyoming Migration Initiative at the University of Wyoming, is the lead author of a November 2020 report, “Ungulate Migrations of the Western United States: Volume 1.” This report resulted from a first-of-its-kind collaborative effort between federal and state agencies and contains maps of more than 40 big game migration routes in Arizona, Idaho, Nevada, Utah, and Wyoming. The U.S. is the first country to have produced these types of standardized migration maps for ungulates (hooved animals) across species and jurisdictions and to archive them in a single place.
This interview with Kauffman has been edited for clarity and length.
A: We know that mapping these migrations is becoming increasingly important as the footprint of fences, roads, subdivisions, energy production, and mineral development in the West continues to expand, making it more difficult for animals to complete their migrations. The science tells us that migration is a key behavior that allows herds of ungulates to find forage or escape deep snow, as two examples, and thus maintain their productivity. This report is the first attempt at mapping migrations with detailed information that provides a path to manage and conserve them.
A: Numerous states have already proved just how effective detailed migration maps like the ones in this report can be. They’re key to ensuring that critical on-the-ground conservation projects are being prioritized. They’ve helped managers and conservationists identify the most critical places for wildlife crossing structures, wildlife-friendly fence removal or retrofitting, and conservation easements that prevent housing developments. They can also help guide energy development on federal lands.
A: In Wyoming, when my colleague Hall Sawyer mapped the Red Desert to Hoback migration, the world’s longest mule deer migration that’s been mapped to date, we were able to identify a 360-acre private parcel that created a quarter-mile bottleneck that several thousand mule deer had to squeeze through. With detailed maps in hand, conservation groups learned that the parcel was up for sale and slated for housing development—so the Conservation Fund was able to purchase it and turn it over to the state to manage as a Wildlife Habitat Management Area. As a result, the fences that contributed to the bottleneck were torn down, allowing the thousands of migratory mule deer to pass through with fewer barriers.
A: State wildlife agencies are charged with managing wildlife herds and their migrations, and there’s a long history of these agencies capturing and tracking animals to better understand how they use the landscape. The state agencies have conducted studies to generate a wealth of GPS movement data and have been eager to apply the statistical methods to turn that tracking data into detailed migration corridors to be included in planning. These types of tracking studies have been a hallmark of state-led science, conservation, and management.
A: Yes. The states have been leading the effort to collect data, and their work, combined with the collaboration with USGS and other federal agencies, has meant that the corridor mapping team has been able to produce detailed maps using the most current methods and approaches.
A: This was certainly a team effort. In addition to the state wildlife departments, multiple federal agencies conducted studies to collect the animal tracking data that we use to map migrations. This collaboration was especially apparent in the greater Yellowstone ecosystem, where we worked together with Yellowstone National Park, Grand Teton National Park, the United States Forest Service, the National Elk Refuge, the U.S. Fish and Wildlife Service, and the Bureau of Land Management.
A: It’s really important because it’s the same type of collaboration that’s required to manage and sustain these migrations, which themselves traverse state and federal boundaries and a checkerboard of land ownership.
A: What was surprising and very interesting to see was that migratory behavior is very common across all the Western states. As a researcher, most of my work is focused within Wyoming, but as the broader team was working on all these maps across the region it became very clear that the behavior of migration is widespread and prevalent across multiple ungulate species. Looking at all the migration routes and corridors in this report gives you a very clear picture that migration is a required behavior for these herds to thrive in diverse Western landscapes.
A: The states in volume 1 of the report—Arizona, Idaho, Nevada, Utah, and Wyoming—were simply the first states to participate in the mapping team when we started in 2018. Numerous other Western states, such as California, Montana, New Mexico, and Washington, joined the team in 2019. We’re analyzing corridors from these states now, and we’ll publish it later this year in volume 2.