Chris Packham, Michaela Strachan and Martin Hughes-Games broadcast live from the Wildfowl and Wetlands Trust's Slimbridge reserve for the final programme of the series. As autumn draws to a close, Chris and Martin track down nature's ultimate winter survivors in the moorland and mountains of the Scottish Highlands. Guest presenter Liz Bonnin is also in Scotland, exploring the wildlife of the Caledonian forest, and reporting on what can be done to protect it in the future. Meanwhile, Michaela has the latest from Slimbridge, as the numbers of overwintering wildfowl build to a spectacle of 35,000 birds.