An incredible round trip is the migration route of the Arctic Tern (Sterna Paradiasea): from the Arctic it can reach the Antarctic and back  ...even more than 40.000 km !!!!!!!!! following an endless spring..the imagine below shows the main routes of a such astonishing flight. That is the longest migration recorded  on the planet. One of the routes follows the whole America West Coast, linking Alaska to Fireland and further up to Antarctica. 
below an exemple of what this impressive globe trotter is able to do: 
"An Arctic Tern found dead in Southern New Zealand flew 25,000 kilometers, or 15,500 miles, from Sweden", a spokesman for the Swedish Museum of Natural History said "It is the farthest ever recorded migration of a tagged bird in Sweden," said the spokesman, Thord Fransson, who oversees the tagging and release of birds..The tern was tagged in June in the northern Swedish province of Haelsingland. It was found dead Dec. 1 on Stewart Island in New Zealand. .The distance between the two locations is 17,500 kilometers, but the bird flew south along Africa's west coast, passed South Africa and the turned east, researchers surmised..Fransson said the museum tags its birds with small aluminum rings, provided with location and identification data on the birds, but the tags do not offer a blow-by-blow account of where they have been."    
arctic tern photo is a Willem Schipper courtesy & copyright