This is the first systematic owl checklist for over 50 years to include subspecies and synonyms. The book provides information on the type, locality, habitat and distribution of 220 owl species and 539 taxa, as well as the location of museum collections of skins and mounted specimens, and references to owl illustrations. In addition to scientific names, the common names of each species in English, German, French and Spanish are listed. The checklist is complemented by many beautiful owl drawings and by watercolours illustrating owl species that have been newly described or rediscovered within the last 20 years.

Owls are enduringly popular birds, but due to their nocturnal habits most species are difficult to see well. The plumages of many species are cryptic and difficult to separate by plumage alone. This problem is compounded by the different morphs that many adopt. This book fully describes every known species and subspecies of owl, as well as presenting the latest evidence on owl taxonomy, based on DNA work and vocalisations. Because voice is vital in owl identification, much emphasis is placed on it in the book and sonograms are provided for many species.