The draft of the bird section of the guide was so enthusiastically received (the reviewers did not want to part with their drafts) that we published it separately as a stand-alone book.  It is remarkably easy to use and is now carried by everyone from environmental educators to back country rangers. The first thing that most people notice about birds is color and size rather than subtle field marks. This inspired me to create a unique organizing system that assumes no prior birding knowledge on the part of the reader. Color-coded keys eliminate the time-consuming frustration of thumbing randomly through a guide, and a cross-index is also included for more advanced birders. All this in a format that is simply organized, lightweight, and small enough to tuck inside a pocket. Read published reviews.