During the past few years I have been told repeatedly by friends and my Smithsonian Institution Press acquisitions editor, Peter Cannell, that my Hummingbirds of North America should be revisited and revised, but I have always found it more interesting to undertake new books than to wrestle with updating old ones. However, during a chance meeting in the summer of 1995, my old friend Luis Baptista urged me not only to revise my original book but also to add the strictly Mexican species of hummingbirds. That sounded like an exciting idea, so I immediately began to determine what was needed to bring it about.
I soon decided that the Isthmus of Tehuantepec represents a much more meaningful and biologically defensible terminus for a book on North American hummingbirds than the Mexican–Guatemalan border, and by limiting my coverage to species that breed north of that region I would need to add only 25 new species accounts to my text coverage. The earlier book had described 23 species, although the inclusion of one of these (the Antillean crested hummingbird) was based on very questionable evidence as to its historical continental occurrence, and I have eliminated it from the present edition. Thus, the present book includes a minimum of 47 so-called “species,” although several of these populations are admittedly complex species groups that are regarded as two or more species by various authorities.
I have followed the comprehensive world checklist by Sibley and Monroe (1990) for recognizing both species limits and taxonomic sequence of species, but have not always followed that reference for recognizing generic limits. Nor have I followed the accepted taxonomy of the American Ornithologists’ Union (AOU) in several cases, but wherever my terminology differs from that of the AOU I have provided the currently accepted AOU nomenclature, based on the most recent Check-list of North American Birds (AOU, 1983) including relevant supplements. A new edition of this checklist should appear soon, and it may include additional taxonomic changes appearing too late to incorporate into this text.
To illustrate the 25 newly included species, I obtained the help of Mark Marcuson, who on short notice produced four wonderful watercolor plates, depicting males of each newly included species. James McClelland kindly allowed me to reprint the 16 stunning watercolors of 22 hummingbird species that he had painted for my original volume. I also was fortunate to obtain the permission of Sophie Webb to reproduce four of her splendid paintings of 56 taxa of North American and Central American hummingbirds from A Guide to the Birds of Mexico and Northern Central America (Howell and Webb 1995). Her paintings not only illustrate male, female, and immature plumages of these species, but also include several additional forms that are either peripheral Central American species or represent recognizable endemic Mexican races if not biologically distinct sibling species. I also relied heavily on Howell and Webb’s wonderfully pioneering field guide in drawing my range maps for these many Mexican species, and gratefully acknowledge its importance in facilitating this component of my book. I also used Howell and Webb’s vernacular nomenclature for most English names of hummingbirds, including those several forms here considered as races but which may be recognized as distinct species after more is learned about their ranges and biologies.
In addition to the help of these persons, I am especially grateful to the Field Museum in Chicago, and in particular to Dr. Daniel Willard of the Bird Division, who arranged for the loan of hummingbird specimens. Dr. Willard also provided me with valuable museum specimen data on hummingbird weights. Associate Librarian Benjamin Williams also very kindly allowed me to examine references in the museum’s rare book collection.