A Wildlife Conservation Society and National Park Service study suggests the pronghorn antelope of the ecosystem that includes Yellowstone and Grand Teton National Parks might soon disappear.
The pronghorn antelope travels more than 400 miles between fawning grounds and wintering areas, second only to caribou in the Arctic for long-distance migration in the Western Hemisphere.
But scientists say the isolated population of the remaining 200-300 animals could disappear because of continued development and human disturbance outside the parks.
The study says pronghorn have used the disappearing migration route in and out of the Yellowstone ecosystem for at least 6,000 years.
"It's amazing that this marathon migration persists in a nation of almost 300 million people," said Wildlife Conservation Society researcher Joel Berger, the study's lead author. "At the same time, the migration is in real trouble, and needs immediate recognition and protection. An entire population from a national park could be eliminated, leaving a conspicuous gap in the ecology and function of native predator-prey interactions."
The research appears in the journal Biology Letters.