The fourth edition of this popular field guide adds some valuable features, including updated maps and taxonomic classifications. A new quick-find index of common groups refers experienced birders to the right page, fast, but wont be much use to novices. Nevertheless, the books organization is clear, the illustrations are realistic and more colorful than ever, and the range maps are easy to understand. The guide covers all North American bird species, including seabirds. In his introduction to the new edition, Cornell ornithologist John W. Fitzpatrick motivates birders of all levels, extolling the virtues of this field guide in helping ordinary citizens add to the store of scientific knowledge. And hes right: marking the little checkboxes in the index as you spot each species is satisfying science that can be done by anyone, including kids. Another delightful feature is the phonetic spellings of bird calls, such as the kakakowlp-kowlp of the Yellow-billed Cuckoo or the few-few-fawee of the Western bluebird. This remains one of the best portable bird guides in publication, tough enough to take in the field, but detailed enough for hours of armchair browsing. 800 illustrations, 630 maps.