4. Winter

It is late January and in the western Highlands of Scotland, and it's unusually warm, even at night. The warmth has brought red deer out of hiding. With no snow or bitter winds to contend with, they're heading back to the hilltops, where there's plenty of heather to eat. Cameras also focus on the Shetland Isles during the winter solstice, and mountain hares in the Cairngorms.