These delightful silvery-grey and white birds have long tails which have earned them the nickname ‘sea-swallow’. They have a buoyant, graceful flight and frequently hover over water before plunging down for a fish. They are often noisy in company and breed in colonies. They breed along coasts with shingle beaches and rocky islands, on rivers with shingle bars, and at inland gravel pits and reservoirs, feeding along rivers and over freshwater. Migrating birds can be seen offshore in autumn. They are in the UK throughout the summer – they arrive in April and leave in August and September. They are most obvious when feeding young as they will fly some distance for food, returning to the nest site with a fish.