“Animals Are Losing Their Vagility, or Ability to Roam Freely” By Jim Robbins, Feb. 19, 2018

https://www.nytimes.com/2018/02/19/science/migration-animals-west.html

“Following an ancient rhythm, [pronghorn] migrate more than 200 miles. After thousands of years, biologists are concerned about the future of this migration pattern.” (Robbins, 2018)