The present work treats 296 species and 33 additional subspecies (329 forms in all) of birds considered by me to be valid and to have been reliably recorded within the boundaries of Kentucky from the earliest times up to and including December 31, 1960. In general, a species was considered to have been reliably recorded when (a) an extant specimen from the state has been a vailable for examination in the course of the work, (b)(1) when a specimen from the state has at some time been examined in the hand of someone capable in my opinion (2) of accurately identifying it, (c) when one or more individuals of the species have been well observed in the field, either on one occasion by three or more people (collectively capable in my opinion, of making identification accurately), or on repeated occasions by one person (similarly deemed capable). While the taking of documentary specimens is definitely to be encouraged as a matter of scientific principle, the rapid improvement in techniques of field identification has made the acceptance of the last criterion (c) rather general in recent years; judiciously applied, it requires, I think, no special defense today.
An additional 17 species are discussed in a hypothetical list reserved for cases where the observations do not quite satisfy at least one of the above criteria (borderline cases in either the main or the hypothetical list are discussed wherever appropriate). These would bring the total to 315 species and 346 forms.