Nightjars and their allies are a curious, fascinating, and remarkably varied group of birds that are found throughout the world. This largely nocturnal group has many specific adaptations for night time activity and some species alter their behaviour according to lunar cycles. Until now, the existing literature has lacked information about their biology or evolution. This book rectifies these omissions in a comprehensive account. The 118 species accounts provide details of coloration, plumage, moults, geographical variation, body measurements, habitats, behaviour, conservation, and evolution and are backed up by a comprehensive bibliography. The more general, introductory chapters review evidence about the group's evolutionary ancestry and place the birds' distributions, behaviour and physiology in an evolutionary context. The 23 superb plates by Martin Woodcock illustrate all the species, with behaviour and subtle variations depicted by delicate halftone drawings.