Since the publication of the first volume of the Handbook of the Birds of the World, more than 20 years ago, there have been numerous taxonomic changes and revisions.
In order to address and document these changes, the HBW team and the BirdLife International Taxonomic Group decided to pool their taxonomic expertise to prepare a carefully studied checklist. In the HBW and BirdLife International Illustrated Checklist of the Birds of the World, Volume 1: Non-passerines (2014) and Volume 2: Passerines (2016), a modern, broad version of the Biological Species Concept (BSC) was applied, with the aid of the scoring system to evaluate differences in morphology, vocalizations, ecology and geographical relationships published in Ibis by Tobias et al. (2010) . Even though taxonomy always involves an element of subjectivity, we believe that using this system has important advantages in terms of consistency, repeatability, transparency and taxonomic stability. Click here for an outline of the Tobias criteria from the Introduction to Volume 1 of the Checklist.
This assessment resulted in 22 lumps for the non-passerines and 54 lumps for the passerines, as well as 462 splits for the non-passerines and 627 splits for the passerines, compared with the taxonomy presented in the HBW series. There were also many changes of genera and reorganization of subspecies, helping us to better understand the relationships between the taxa. Furthermore, the macrosystematics was overhauled, bringing to light interesting relationships between and among families, subfamilies, tribes and genera.
All of these taxonomic changes have been applied to the non-passerines (Sept 2014) and the passerines (March 2016) in HBW Alive. Besides the reclassification itself, users will also find updates to these important elements:
- MAPS: Newly revised distribution maps for all species, with country borders included, researched and prepared by BirdLife International, NatureServe and the HBW team.
- ILLUSTRATIONS: New and improved figures, including those to illustrate split species and to correct detected errors from the HBW series.
- RANGES: Detailed and updated descriptions of ranges for all species and subspecies.
- TAXONOMIC NOTES: Changes and other relevant issues fully explained under Taxonomy for each species.
- REFERENCES: The c. 5000 references given in the two Checklist volumes are conveniently linked in the HBW Alive texts and quickly give users detailed information about the source.
- IUCN RED LIST CATEGORIES: Current official IUCN category of each species from the 2016 BirdLife International/IUCN Red List of Threatened Species.
- NAMES: Revised Latin and English species names, as well as updates in French, German and Spanish names, and in other common names in English when appropriate.
- SUBSPECIES GROUPS: Colour-coded subspecies groups marked to highlight distinct forms and their relationships.