Overview: As part of the Autumnwatch season Green Balloon Club team are having a good look at Autumn - how the leaves change colour and whether it is possible to preserve their lovely shades. Jelly pays a visit to Bill Oddie and finds out what's happening in his bird boxes at this time of year. Many birds migrate now, but Jay and the Ground Crew have a look at the ones that stay at home and find out how experts research their lives.