British Isles: A Natural History - Season 1 Episode 4 Islands Apart

Alan ventures 50 metres below the Channel, scales an ancient tree in the New Forest and stalks red deer in Scotland to tell the story of how island Britain was created. He searches for clues across the country, discovering tropical nickar nuts in Scotland, palm trees growing at latitudes where polar bears should feel more at home and watching whooper swans in Cambridgeshire who arrive from Siberia for Britain's milder winters.