The format for the guide is to present a color photograph of each species, for which we tried to obtain a photo of a local specimen. The photos are accompanied with the following information to aid in identification:
Scientific name: Based on our understanding of the current nomenclature of the species; subspecies names are included when they can be distinguished in the field.
Common name: The name used follows Robert Stebbin's 1985 "A field guide to western reptiles and amphibians" (Houghton Mifflin Company).
Size: We present the minimum and maximum adult snout to vent lengths for all species except for turtles for which we present carapace lengths. The measurements we present are based on the literature and unpublished data we have been collecting for the last two years. In some instances we have measurements for 1,000+ individuals of a species and where we differ from the literature we have used our data.
Distinguishing characters: We have tried to provide simple visual characteristics to help identify the species in our region. We have tried to make the terminology as non-technical as possible but still found it necessary to include a glossary of diagrams in the back of the book to illustrate characteristics with which readers may be unfamiliar.
Juveniles: If there are any obvious ontogenetic changes in the species, then we describe them here. We present a page of tadpole illustrations to help in their identification, located after the section on frogs and toads.
Dimorphism: If there are known obvious morphological differences between the sexes in a species, then these are described in this section.
Similar species: We describe characters that are useful in telling similar looking species apart, especially if these species occur in sympatry.
Additional notes: In this section we briefly point out distributional restrictions, natural history observations, or behavioral traits of a species or subspecies.
The order of species in the book does not necessarily reflect taxonomic or phylogenetic relationships, but rather is based on general similarity in appearance. Species which are most often confused are kept close together in the book.