大象传媒

Iolo Williams visits Cemlyn Bay on the north coast of Anglesey, home to one of Britain's biggest tern colonies. Over a thousand pairs of Sandwich terns, as well as Common and Arctic terns flock here to breed in the summer, making it a site of international importance. Before the birds arrive, volunteers from the North Wales Wildlife Trust are hard at work. Each spring the volunteers wade through the cold water to the lagoon's islands to prepare the site for the returning terns, and put out nesting boxes to encourage Roseate terns to breed at Cemlyn Nature Reserve.