If your social media feed has ever featured a viral video of mustangs galloping across the American West, you're aware of the symbolism of wild horses: freedom, determination, the rugged frontier spirit. It's therefore somewhat surprising to learn that a major conservation success story for the Great Basin region of the last decade involved removing thousands of horses and burros from a public land refuge.
The subject of this scientific discussion is the Sheldon National Wildlife Refuge, a 575,000-acre tract of high desert in northwest Nevada. According to a 2012 federal assessment conducted by the US Fish and Wildlife Service, 44 percent of the refuge's streams and 80 percent of its springs had been "severely degraded" by feral horses and burros by the year 2002, animals that are not native to the area and that originated from ranch stock that were either set free or left behind decades earlier.
