With the publication of volume 13 (of 16, final volume out in 2011), some 174 of approximately 200 families of birds have been covered in the internationally acclaimed series Handbook of the Birds of the World (HBW). Volume 13 follows the classic layout of HBW by starting with a highly informative essay, which in this volume reviews the fascinating subject of bird migration (written by Ian Newton). The main body of the book covers an impressive 595 species in the following families: Remizidae (penduline-tits: 13 species), Aegithalidae (long-tailed tits: 13), Sittidae (nuthatches: 27), Tichodromidae (Wallcreeper: 1), Certhiidae (treecreepers: 10), Rhabdornithidae (Rhabdornis: 3), Nectariniidae (sunbirds: 132), Melanocharitidae (berrypeckers and longbills: 10), Paramythiidae (painted berrypeckers: 2), Dicaeidae (flowerpeckers: 44), Pardalotidae (pardalotes: 4), Zosteropidae (white-eyes: 98), Promeropidae (sugarbirds: 2), Meliphagidae (honeyeaters: 175), Oriolidae (orioles: 30), and Laniidae (shrikes: 31).
These 16 families, presented in a modern taxonomic framework (e.g., Barker et al. 2004, Jønsson and Fjeldså 2006, Johansson et al. 2008), span the songbird tree of life. From an ecological perspective, the sequence of families rather pleasingly encompasses nearly all the major creeper and nectarivore groups of traditional classifications, ending with the shrikes (shrike-like birds being the focus of the forthcoming vol. 14). I was particularly pleased to see that the editors had resisted attempts of some classification systems to lump traditionally recognized families such as the flowerpeckers, sugarbirds, and sunbirds together in the Nectariniidae or the painted berrypeckers with the berrypeckers and longbills in the Melanocharitidae. At the same time, the validity of some of these families is unlikely to be retained in the future. For example, there is now convincing evidence that species in the Rhabdornithidae belong in the Sturnidae (starlings; Cibois and Cracraft 2004, Zuccon et al. 2006) and that the white-eyes are part of the babbler radiation (Timaliidae; Gelang et al. 2009). One cannot fault the editors for this, for the taxonomic sequence was set several years ago and many of these results are recently published. But this does highlight a point that readers who do not closely follow avian systematics (e.g., general bird enthusiasts and comparative biologists, among others) will find somewhat frustrating. With the advent of cheap and efficient methods for collecting DNA sequence data, together with several new methods of analysis, avian systematics is at present undergoing a revolution, with new discoveries being made almost monthly. One of the most recent and dramatic (duly noted in the honeyeater chapter) pertains to the discovery that the two genera Moho and Chaetoptila, the “Hawaian honeyeaters,” are more closely related to waxwings, Neotropical silky flycatchers, and Palmchats (Dulus dominicus) than to Australasian honeyeaters (Fleischer et al. 2008). Although such large changes in taxonomy are likely to remain limited, others such as generic-level revisions are not. A simple case can be illustrated with the Nectariniidae, where use of molecular sequence data has revealed the lack of monophyly for nearly all the presently recognized 16 genera (Bowie 2003). My point is not to criticize the book—far from it: many of the authors do an excellent job of highlighting problematic taxonomy and aspects that are likely to change in the future— but rather to sound a cautionary note. The present taxonomy, at this fascinating time of massive flux within the classification of birds, is unlikely to remain stable even in the near future.
Aside from a detailed review of the systematics of each group, the beginning of each family chapter includes detailed sections on the ecology, behavior, and status of the taxa in each family, which make for fascinating reading. These texts are excellently written by experts on individual families, and in several cases they include data from studies that were published after this book (e.g., the discussion of Hawaiian honeyeaters cited above). This initial introductory overview of each family is followed by detailed species accounts together with excellent color maps of distribution ranges that are easy to interpret.
The book contains 60 color plates illustrating all species and including “all significant sexual and subspecific differences.” As a whole this goal is met, although for large families such as the sunbirds and honeyeaters not all “significant” taxa are illustrated; however, the quality of the plates is truly exceptional. A test, which I often use for my favorite group of birds (the sunbirds) when consulting a new field guide or monographic compilation, is to see how well the artist has illustrated the Rufous-winged Sunbird (Cinnyris rufipennis), a species first described in 1983. Despite an illustration that appeared with the original species description, its depiction in subsequent texts has varied from fantasy (e.g., Stevenson and Fanshawe 2002) to average (Cheke and Mann 2001) to exceptionally accurate (this book).
I own all the previous volumes of the HBW, and I admit that the one aspect of these books that gives me the most pleasure is the out-of-this-world photography. Volume 13 is no different, including 536 stunning photographs. This lavish illustration, together with an informative text (over 6,000 references, including a specific section devoted to bibliographic details of every genus, species, and subspecies accepted by HBW) makes this one of those very rare books that can pass as both an outstanding coffee-table book and an exceptional reference. To those who have already purchased the previous volumes: you will not be disappointed, for this one lives up to the very highest standards set by the HBW production team. To those who have not yet invested in a volume of the HBW series and have an interest in Old World birds or some of North America's more enigmatic species and families—for example, Verdin (Remizidae: Auriparus flaviceps), Bushtit (Aegithalidae: Psaltriparus minimus), Brown Creeper (Certhiidae: Certhia americana), and the nuthatches (Sittidae: Sitta spp.)—buy this book! It will prove a fundamentally important reference and a fascinating read, and provide a great sense of pleasure when you come back to it time and time again.