The commitment with the Handbook of the Birds of the World Series has been to cover in detail and illustrate every species of bird in the world. This task has taken from 1992, with the publication of Volume 1, to 2011 with the publication of Volume 16, covering the last families of birds. However, a number of species genuinely new to science have been described since the publication of their respective volumes, and therefore are not featured in the 16 volumes of HBW. The Special Volume covers and illustrates all of these species, 69, with texts, plates and distribution maps in the classic HBW format.

Also, in response to the many requests from subscribers over the years, the Special Volume includes a comprehensive, global index to the collection, a useful tool which will enable users swiftly to find the species they are searching for in the more than 12,500 pages of the 16 volumes.

An unexpected addition to this volume is a section including the original scientific descriptions of 15 species, all totally new to science. These descriptions are the combined work of a number of renowned Amazonian ornithologists, and highlight the massive importance of the world's largest area of tropical forest.

The inclusion of all these scientific descriptions in the Special Volume is of some additional significance because to find so many species described simultaneously, in the same paper, one has to go back well over a century. From the initial projected list for the volume of 53 species, its a pleasure now to present an overall total of 84 new species, including those described directly in the volume.