Dr Chris Redfern will talk to us about Arctic terns.

Arctic terns are renowned for the global scale of their migration. The routes taken by individuals can be determined using small electronic ‘geolocators’ attached to a leg ring. These devices have been fitted to Arctic terns breeding on the Farne Islands, Northumberland, and need to be recaptured the following year to download data. A particular characteristic of the Farne Islands population has led to a high return rate of data which have given amazing insights into the annual migration of Farne Islands Arctic terns and how this differs from Arctic terns breeding further north in the North Atlantic. After breeding, most birds from North Atlantic populations migrate directly south through the Atlantic to the Weddell Sea of Antarctica. In contrast, birds from the Farne Islands turned east at the tip of South Africa and crossed the Southern Indian Ocean before dropping south to East Antarctica. This may be a migration strategy retained since the last ice age. In coastal Antarctica, krill associated with fragmenting sea ice is an important resource sustaining their lifestyle and annual moult. Reductions in sea ice as a result of climate change threats the long-term future of Arctic terns. Northward spring migration through the Atlantic is rapid and likely timed to utilise foraging resources in the Antarctic and along the way to ensure arrival at the colony at the appropriate time and condition for breeding.

Photo by Bernd 📷 Dittrich on Unsplash