The information on animal habitat, food sources, and behavior is fascinating and unforgettable. Charles Fergus has forgotten more about area animal life than most people will ever know. This is one book that never leaves my nightstand, as it is organized well and is my "go-to book" for esoteric questions about mammals, birds, reptiles and amphibians in Pennsylvania.
However, it is not a field guide. The black and white illustrations are a disappointment; very crudely drawn, and not every species has an illustration. Thus, it is difficult to compare closely-related species. For instance, Mr. Fergus describes 13 varieties of hawks, eagles, falcons,kestrels and merlins, yet there are only a meager 6 illustrations for the section. Perhaps in the next edition, Mr. Fergus will collaborate with a better illustrator and will include more, realistic, and (GASP) COLOR drawings or photos of these animals for his readers.
Despite the lack of illustrations, this book is a great reference material. Use it in conjunction with other field guides and you won't be disappointed in its scope.