The idea for this book was the result of the chance input of two individuals: Nik Borrow, who first raised the issue of picathartes speciation, and Jon Fjeldså, who kindly provided the answer. In their different ways, both were responsible for kick-starting this three-year project – and for that I am especially grateful.
I would also like to thank the many professional guides whose field skills enabled me to observe first-hand the leading characters of this book, and in so doing opened my eyes to the bewildering variation and complexity of the world’s avifauna. I am also indebted to those scientists who replied to my pestering emails, forwarded relevant papers, provided helpful suggestions, and allowed me to use their photographs and artwork. I have listed all of the above in alphabetical order: Peter Alfrey, Craig Benkman, Charles Bishop, Nik Borrow, Leslie Christidis, Stefan Christmann, Julia Clarke, Joel Cracraft, Willie de Vries, Jared Diamond, Jon Fjeldså, Ewan Fordyce, Nicole Fuller, Robert Furness, Peter Garrity, Chris Gaskin, Peter and Rosemary Grant, Lucy Hawkes, Jason Horn, Des Hume, Walter Jetz, Daniel Ksepka, Tim Laman, Markus Lilje, Kevin McCracken, Andrew Meade, John Megahan, Jin Meng, Steve Mills, Ian Montgomery, Pete Morris, Rolf Nussbaumer, János Oláh, Nuno Oliveira, Mark Pagel, Tony Parker, Eduardo Patrial, Lars Petersson, Richard Prum, Petra Rank, Forrest Rowland, Edwin Scholes, Graham Scott, Victor Soria-Carrasco, Chubzang Tangbi, Shaun Templeton, Gavin Thomas, Daniel Thomas, Andreas Trepte, Mark van Beirs, Katrina van Grouw, Dylan van Winkel, Chris Venditti and Christopher C. Witt. I am especially indebted, however, to Gerald Mayr, who kindly checked the manuscript for errors relating to palaeontology, and whose encyclopaedic knowledge and attention to detail has saved me many a blush.
Acknowledgement of all those who helped, of course, does not imply their endorsement of the views expressed in this book; I alone am answerable for them. Similarly, any errors of fact or omissions are entirely my responsibility.
Thanks must also go to Nick Davies and Gareth Dyke for their confidence in the project, and to Frank Ryan for his gentle editorial guidance. I would like to thank my son Mark for his patience in producing the many drafts of the figures. I am indebted to the skills of copy-editor Hugh Brazier, whose eagle eyes have spotted more grammatical and factual errors than I would care to admit. I am also grateful to Nigel Massen and his team at Pelagic Publishing, all of whom have helped transform my words and pictures into the book you now hold in your hands.
Last of all, but by no means least, I would like to thank Janette, my wife and birding companion, who convinced me that the writing of this book was not beyond me, and who provided the support needed during the times of self-doubt.