The Sibley Guide to Birds This is the most important new birdwatching field guide since the 1934 edition of Peterson's "Field Guide to Birds". What makes the 546-page "Sibley Guide" so revolutionary is the number of illustrations. Whereas most field guides have 1-3 photos or illustrations of each species, Sibley includes seven or more: showing males, females, and juveniles sitting and in various stages of flight. Identifying those tiny, hyper warblers is now MUCH easier. Covers 810 species throughout North America. Range maps for each species.