KLAUS MALLING OLSEN / HANS LARSSON
The standard text on the identification of the northern hemisphere's gulls, Gulls of Europe, Asia and North America covers the plumage variation through age and subspecies of all 80 species in the region. With exhaustive coverage, detailed maps, and superb plates and photos, Gulls of Europe, Asia and North America remains the definitive work on these birds, which represent the trickiest of all ID challenges.