What animal holds the record for the longest migration on Earth?

The answer

The Arctic tern holds the record for the longest migration of any animal. Breeding in the Arctic and wintering in Antarctica, a single tern travels roughly 71,000 kilometers annually. Over its 30-year lifespan, that totals approximately 2.4 million kilometers - equivalent to three round trips to the Moon. In 2016, a study published in Current Biology using geolocator tags recorded one Arctic tern flying 96,000 kilometers in a single year by following an 'S'-shaped Atlantic route to exploit prevailing winds. Other record holders include bar-tailed godwits, which completed a nonstop 13,560-kilometer flight from Alaska to Tasmania in 2022.