“Animal migration: an endangered phenomenon? Timely international action can sustain this inspiring natural process before it becomes a crisis.”

By David S. Wilcove, Spring, 2008 https://issues.org/wilcove/

“Although animal migration may be a ubiquitous phenomenon, it is also an increasingly endangered one. In virtually every corner of the globe, migratory animals face a growing array of threats, including habitat destruction, overexploitation, disease, and global climate change. University of Montana ecologist Joel Berger has estimated that 58% of the elk migratory routes and 78% of the pronghorn routes in the Greater Yellowstone Ecosystem have been lost due to development.”