National Geographic Bird colouration by Geoffrey E. Hill
The first non-academic work on colouration and plumage and their key role in avian life. More than 200 gorgeous photographs highlight the explanations of the essentials: what colour is, ornithologically speaking; how it is produced and measured; how birds use colour to attract mates and deter competitors; how birds perceive colour; and how colouration varies across species by sex, season, and age.