For the more information about the geologic resources of the National Park Service, please visit http://www.nature.nps.gov/geology/.


Why migrate?

Bison herd crossing stream.
Bison migration.

The annual synchronized movements of millions of individuals participating in a journey that has repeated itself for thousands of generations, captivates the imagination. Migration is a strategy to survive, allowing wildlife to:

  • Track seasonal food resources
  • Escape dry seasons
  • Avoid harsh winters
  • Evade heavy predation during reproductive periods

Ecological Roles

Migratory species may have strong ecological influences and fulfill important ecological roles, including:


Eagle Bison and Elk Elk
Predators Grazers Prey
     
Monarch Butterfly Band Tail Pigeon  
Pollinators Seed Dispersers  

Last Updated: May 06, 2015