The Arctic tern holds the record, making a round trip of 70,800 kilometres (44,000 miles) a year. It spends summer in the Arctic and then flies halfway around the world for a second summer in Antarctica. Being seabirds, Arctic terns can feed on fish and krill along the way, but the bar-tailed godwit is a wader and flies an incredible 11,430 kilometres (7,100 miles) from Alaska to New Zealand in just nine days, without once stopping to eat, drink or rest. The lifetime achievement record, however, must go to the Manx shearwater. This species migrates between Norway and the Falkland Islands each year and, since they can live for up to 50 years, some individuals are estimated to have flown 8 million kilometres (5 million miles) – that’s more than ten round-trips to the Moon!
Answered by Luis Villazon.