Drawing on years of field work around the world, Klaus Malling Olsen discusses field identification for each of the seven species of skua, explaining structural and behavioral differences as well as the most important plumage details. He also provides information on vocalization, molt, plumage, geographical distribution, migration and wintering grounds, breeding biology, and relationship to humans. The text is enhanced by color plates, black-and-white sketches prepared by Swedish artist Hans Larsson, and numerous photographs, many published for the first time. The illustrations show the variation in breeding and juvenile plumages and capture the birds in flight and at rest. There is also a comprehensive bibliography to the literature on skuas.

"A real step forward in field ornithology. This is an impressive book that pulls together in unusual detail the current knowledge and thinking on skua taxonomy, much new invaluable material on distribution and identification, and information on various other aspects of their biology". -- Tony Marr, member, British Ornithologists Union Records Committee