Peterson Field Guide to Advanced Birding

This Peterson Field Guide by Kenn Kaufman explains exactly how to solve the most challenging identification problems of North America's birds. Kaufman's guide covers the 35 most difficult groups, and a wide variety of birds from winter loons to fall warblers, jaegers to chickadees. Kaufman also explains concisely and precisely what the identification problems are for each group, and then systematically shows you just how to solve them.