National Trust rangers who keep close watch over Britain’s largest mainland colony of Arctic Terns at Long Nanny on the coast of Northumberland are holding their breath at a critical time in the breeding season to see whether the colony has managed to escape avian influenza, bird flu, this year.

Arctic Terns migrate from their northern hemisphere breeding grounds to Antarctica and back – a journey of up to 50,000 miles each year.

The coastal site is typically a safe breeding ground for both the Arctic and Little Tern, the latter being the second rarest breeding seabird in the UK, which has a much shorter migration to and from the west coast of Africa, each year.