Arctic terns and their great journeys in search of sunshine

Guest blog by Monika Wojcieszek, RSPB NI Tern Conservation Officer


Bird migration is one of the greatest spectacles of nature.
Each year, millions of birds across the planet embark on a journey looking for food, breeding grounds or milder climate.
Arctic terns have the longest known migration in the animal kingdom. This small, gracious bird, weighing about 100g, travels on average an astonishing 71,000 kilometres a year, covering a record-breaking distance of 90,000km. Arctic terns can live for up to 30 years, and during their lifetime they can travel roughly 2.4 million kilometres - around three times the distance to the moon and back!

Arctic terns breed in polar and sub-polar regions, and their southern range includes the Irish coast. They nest in large colonies, often amongst other seabirds. In Northern Ireland, they come to breed at a few different locations, including Strangford Lough, RSPB Belfast Lough, Carlingford Lough, the Ards Peninsula and the Copeland Islands.
By tagging Arctic terns with geolocators, researchers have been able to map their remarkable journey.
In late July, when days are slowly getting shorter way up north, Arctic terns leave their breeding grounds and start their epic journey south. The route will take them along the west coasts of Europe and Africa, and some birds may venture as far as the Indian Ocean. The birds will sustain themselves along the way by shallow diving for small fish.
By November, they reach the Southern Ocean, where they spend the Antarctic summer. In late April and early May, Arctic terns complete their annual migration by returning to their breeding grounds to raise their chicks.


On their journeys, the birds will face many challenges, including bad weather, predators, exhaustion and starvation. However, this perilous journey has many advantages. Each year, by spending summer in both hemispheres, Arctic terns experience more sunlight than any other animal. Cool polar waters are also rich in nutrients and provide good food supply for terns.
Despite enormous distances covered, many Arctic terns return to the same area or even same colony where they hatched, to raise the next generation of these ultimate travellers.

Photo credits: Joel Rock (top), Shane Wolsey (middle), Ian Enlander (bottom).