Big Game Migration from Private to Public Land

Americans are used to thinking of parcels of property as two-dimensional blocks. We have carved landscapes into counties, townships, sections, and acres, and especially in the West, our public lands conform to the same rectangular geometry.

But a growing field of research indicates that, at least to the wildlife we love to hunt, land might be better described in the shape of snaking lines or, at least, irregular polygons. The research is looking at big-game migrations, and early results indicate that when it comes to routes that best benefit migrating wildlife, we should be thinking of landscapes in at least two additional dimensions, adding elevation and time to our squarish view of the map.

Big-game migrations are getting a lot of attention lately, thanks in part to technology. The ability of biologists to attach small, portable, powerful GPS-transmitting collars to wild animals has provided a trove of data into when, where, why, and how herds move seasonally. And that data has informed wildlife-management decisions: where to improve habitat, when to schedule hunting seasons, and how to effectively move migrating wildlife across interstate highways and around natural-gas fields.

The renewed emphasis on the importance of linear rather than rectangular wildlife habitat has now caught the attention of federal policymakers. In May, the Department of the Interior awarded $2.1 million in federal seed money, which will grow to more than $10 million with public-private matches, to conserve habitat along big-game migration corridors in several western states.

One of the corridors that will receive some of this funding is southwestern Colorado’s U.S. Highway 160 between Durango and Pagosa Springs. Because this stretch of highway perennially leads Colorado in wildlife-vehicle collisions, the funds will go to construction of a wide funnel beneath the roadway, connecting elk and deer habitats on both sides while avoiding traffic.

Research into migration habits has revealed plenty of gems that will enlarge our view of wildlife movements and which landscapes are most valued to transient herds. The work is also revealing the seasonal value of public land.

Andrew Jakes, a wildlife biologist with the National Wildlife Federation whose graduate work studied antelope migrations, points to the value of Yellowstone National Park.

“Although many animals may winter on private lands, they move in and out of the park and the surrounding national forests during summer and migratory periods,” he said. Jakes also points to studies of mule deer that summer in Wyoming’s Hoback Range but winter hundreds of miles away in the Red Desert north of Rawlings.

“They have to negotiate a matrix of private and public lands,” said Jakes, “which illustrates the idea that wildlife do not know human-made borders.”

Or, it appears, the unnatural rectangles that we recognize as features of most maps of the West.

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