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Puffins living on the Farne Islands off the Northumberland coast will be tagged with GPS transmitters this summer a world first for these birds in order to shed new light on their movements and behaviour.

Puffin numbers have fallen dramatically in the past five years, and researchers hope the reasons why will be revealed by plotting their time on the islands and what happens to them when they leave later this month. National Trust warden David Steel says: ‘This has become the case of the disappearing puffins.

Young puffins are successfully fledging each year and it would seem that their staple food, the sand eel, is in good supply, but they aren’t coming back.’ As well as the tags, which are glued on to the birds’ feathers and will map their movements, further work will be carried out using time-depth records. These devices provide information on diving behaviour and sea temperatures, which should help us understand how puffins might be affected by climate change.