In the run up to the Paris Climate Change Conference this edition of Nature's Voice looks at how climate change is affecting wildlife. The RSPB's conservation director Martin Harper talks to Jane Markham about the challenges ahead and we celebrate a success story. Bitterns, their reedbed habitats on the coast threatened by rising sea levels and reduced to a handful of breeding pairs in the mid 1990s, are now flourishing at Lakenheath Fen in reedbeds planted with the help of volunteers.