Welcome to the ABA Identification Vault.
Here you will find articles (in PDF format) pertaining to bird identification, from Birding, and Winging It, and A Bird’s-Eye View.
Over 700 articles—with more being added regularly—searchable and tagged by species mentioned. There are two tabs: one for all of the articles, and the other containing articles pertaining to “fieldcraft”. Those tend to detail field skills applicable to many species—such as understanding molt—rather than how to identify certain species.