Autumnwatch returns for a celebration of UK wildlife. Chris and Martin visit the west coast of Scotland to catch up with the sea eagles of Mull. Since their reintroduction, some 35 years ago, the eagles have proved to be a real conservation success story. Aboard a sea kayak, Martin also explores Mull's coastline - home to otters, seals and eider ducks. On Dartmoor, Nick Baker takes us on his own journey into the world of an oak tree and on the Somerset Levels there's news of another comeback - cranes, living wild for the first time in nearly 400 years.