David A. Christie & James Ferguson-Lees 
Raptors of the World [PDF ebook] 

‘Covering every species of raptor on the planet, this book is perfect for anyone with an interest in birds of prey.’ — Birdwatch This guide covers all the world’s 313 raptor species illustrated with adult, juvenile and selected immature plumages as well as main geographical races.There are illustrations of over 2000 perched and flying birds, some with typical prey and facing texts summarising length, wingspan, male-to-female proportion, shape and flight.The text is further enhanced with line drawings illustrating specific points about identification and behaviour.