For Christmas 2010, I received a copy of a book called Advanced Bird ID Guide: The Western Palaearctic by Dutch birder and bird identification specialist Nils van Duivendijk. It was (still is) a compact, paperback volume — all text, no images — covering every plumage of all 1,300 species and….

Chiffchaffs and willow warblers have been back in the country for a while now, and are singing their little heads off… which is a good thing… because the song is the most reliable way of telling these two very similar species apart. If you don’t hear them, getting a positive….