World’s Longest Migratory Journey May Not Be Threatened By Climate Change

An arctic seabird with the world’s longest migratory journey may be able to navigate dangers posed by climate change, suggests a new study.

The Arctic tern lives in near-constant daylight and travels around 25,000 miles each year – breeding in the Northern Hemisphere and traveling south for the summer.

The new study examined the predicted impacts of climate change on the birds’ annual trips from pole to pole.

The study used current observations of ongoing changes in climate, as well as multiple climactic and Earth System Models, to project changes on the planet by the year 2100.

Researchers examined the likely impacts of climate change on the terns outside the breeding season; investigating changes to prevailing winds and the availability of food at key sites visited by the seabirds.

The terns live in near-perpetual daylight, breeding in the north of the planet and flying to Antarctica to enjoy the summer in the Southern Hemisphere.

Each bird covers enough distance in their lifetime to travel to the moon three times and can live for more than three decades.

The team examined the impacts of two potential scenarios: one ‘middle-of-the-road’ future and another ‘fossil-fueled-development’ future.

The fossil fuel route predicted a decline in primary productivity – the base level of all food chains – in the North Atlantic; a key feeding ground for millions of seabirds and other marine life.

The impacts of the likely decline in Antarctic sea ice on the terns, however, is uncertain.

Projections suggest small changes to prevailing winds would have ‘minimal’ consequences for tern migration except for the Southern Ocean, where strengthening winds may force the birds to change their flight routes.

“Although the Arctic tern is a species of ‘least concern’ globally on the International Union for Conservation of Nature’s (IUCN) Red List, breeding numbers are declining and can be challenging to monitor.

“Climate change is a massive threat to all seabirds, and our study looked at specific aspects of this.

“So, while our findings suggest this species may be resilient, this is only part of a bigger picture for Arctic terns and many other species.

“Meeting carbon emissions targets is vital to slow these projected end-of-century climatic changes and minimize extinction risk for all species.”

Produced in association with SWNS Talker