The first two arctic terns of the season were spotted in Southeast Iceland on Saturday morning, according to the Southeast Iceland Bird Observatory. Their arrival is two or three days earlier than usual. Bird enthusiasts across the country are following along with migratory species as they return to their breeding grounds in Iceland.
The arctic tern makes the longest known migration of any animal, travelling between Arctic and sub-Arctic regions, where it breeds, to the Antarctic, where it winters, each year. Birds that nest in Iceland make a round trip that averages 70,900km (44,055mi) every year between their nesting and wintering grounds. The average arctic tern will travel some 2.4 million kilometres (1.5 million miles) during its lifetime, the equivalent of over three roundtrips from Earth to the Moon.