This geographic tern's 20,000-mile trip gives it the longest migration of any bird
The 
Arctic tern, one of the longest migrators on the planet, can travel a mind... [DOC] [TLE] These Are the Most Extreme Migrations in the Animal Kingdom [PAR] Oct 3, 2013 ... Migrations occur in every major branch of the animal kingdom, from ... the 
cetaceans travel some 5,000 miles (8,000 kilometers) south to give ... the birds 
have the longest recorded annual migration of any animal.