Birds have long held a unique dual role as a model group for scientists and as the focus of birders' passionate quests. Despite centuries of observation, each year brings the discovery and description of several entirely new avian species and hundreds of other taxonomic "splits" or "lumps" based on DNA data. In this arena of continual and increasing taxonomic change, The Clements Checklist presents the most up-to-date and most widely endorsed compendium of the more than 9800 species of birds recognized by the scientific and birding communities.

This completely revised sixth...