It’s Halloween week and Autumnwatch is back – launching a week of special 60-minute programmes celebrating all the very best of our UK wildlife. Broadcasting live from the Dell of Abernethy in the heart of the Cairngorms, Chris Packham, Michaela Strachan, Gillian Burke and Iolo Williams profile this stunning wilderness in its most technicolour season, finding out what autumn means for the iconic wildlife and the animals that live here. In the first programme, they explain exactly what autumn is and how it came to be. Tonight astronaut Tim Peake explains how autumn was born four and a half billion years ago, and we meet a Northumbrian GP who has befriended a colony of North Sea seals. We report on the initial results of the Watch’s largest citizen science project ever attempted - Gardenwatch. Working in conjunction with the British Trust for Ornithology and the Open University, we asked people to survey the wildlife living in their gardens to help scientists build a comprehensive report of exactly what lives on the nation's doorsteps.