Molt in Neotropical Birds: Life History and Aging Criteria

J. Field Ornithol. 89(1):105–107, 2018 DOI: 10.1111/jofo.12241

RECENT LITERATURE Edited by Sabrina S. Taylor [email protected]

BOOK REVIEWS avian taxonomy, breeding systems, migration, behavior, and so on. Historically, molt and Molt in Neotropical Birds: Life His- plumage terminologies applied by ornitholo- tory and Aging Criteria gists were so diverse and confounding as to Erik I. Johnson and Jared D. Wolfe. 2018. make understanding the complexity of bird Studies in Avian Biology, A Publication of molt nigh impossible. The eyes of experts the American Ornithological Society, Volume glazed over, and students in ornithology 51, CRC Press, Boca Raton, FL. xii + 400 sought less impenetrable arenas. Furthermore, pages, > 950 photographs, > 75 figures and because these molt and plumage nomencla- graphs, and > 175 tables and data summaries. tures were based on boreal-centric, seasonal, ISBN 9781498716116. $144 (Hardcover). or breeding terms, their application to less- When I first unpackaged Molt in Neotropi- seasonal tropical species was illogical. Very cal Birds, I was a bit puzzled by the cover slowly, however, over the past century, the photograph. It shows a representatively exo- terminology has been improved. A large step tic and clandestine-looking Amazonian spe- was the introduction by P. Humphrey and K. cies, a Collared Puffbird (Bucco capensis)asI Parkes, in 1959, of their now widely used later learned from page 119, with intricate and regarded “H-P” molt and plumage termi- orange, rufous, and black plumage and a nology, and its subsequent successful applica- large, bright orange bill. However, it tion to Holarctic and Australasian species. appeared to be in the hand and not happy Meanwhile, a few intrepid souls began to cau- about it, looking a bit disheveled, only par- tiously approach molt in Neotropical species, tially framed, and obliquely staring at the and we now have a patchwork of locations photographer, displaying both an annoyed with published information on molt strategies and an amusingly evil look to its partially among avian communities, starting with El cloaked, orange-yellow eye. Wouldn’t having Salvador (Dickey and van Rossem 1938), and one of its wings nicely spread, so emblem- including Trinidad (Snow and Snow 1964), atic of bird molt study these days, been Costa Rica (Foster 1975, Wolfe et al. 2009), preferable? However, immediately afterwards, Cuba (Pyle et al. 2004), central Mexico I asked myself what any of the Æ 10 of us (Guallar et al. 2009), Colombia (Hernandez in the world who are passionate about bird 2012), Chile (Pyle et al. 2015), Venezuela molt would ask: “What the heck are the (Lentino 2016), and Nicaragua (Torrez and molt strategies of this creature?” Crickets. Arendt 2016). Molt in Neotropical Birds, Well, I guess I will just have to turn to page although based primarily on data from one 119 to find out. It then hit me that perhaps location in Amazonian Brazil, not only plugs the cover image perfectly epitomized this a huge hole in our knowledge void, but pro- work’s essence and fundamental necessity. vides a timely and comprehensive update on The look in that eye: a bit annoyed that we where the subject stands to date. will learn something about its molt patterns The book is divided into 39 chapters, an as they apply to Neotropical birds, but deri- introduction, directions for use, and 37 chap- sive because we have such a long way to go. ters consisting of family accounts covering Indeed, there are 4000 + species of 186 Neotropical species (including a few Neotropical birds, and we know nothing Nearctic-Neotropical migrants) found in the about molt patterns for 90% of them. As Amazon Basin. I found the introductory often repeated, the study of avian molt chapter, basically a treatise on bird molt and strategies has lagged well behind those of its application in the Neotropics, thorough,

105 106 Recent Literature J. Field Ornithol. concise, and clear. H-P’s evolutionary species of birds. Although we all recognize the approach to bird molt is nicely capsulized, drawbacks of “definitive” as defined by H-P, e.g., by “...modifications to the sequence, replacing this term with “adult” does not solve timing, and frequency of feather replacement anything, and the carefully crafted and consid- over the last 150 million years have been ered aging cycle codes would no longer apply molded and crafted, with inserted molts to the terminology, e.g., “Second Prebasic blinking on and off across families, genera, Molt (SPB)” would be replaced by “Definitive and species, thus highlighting the wonderful Prebasic Molt (DPB),” whereas the latter plasticity of molt despite being grounded on would be replaced by “Adult Prebasic Molt an annual ritual of full feather replacement” (APB).” I cannot help but generally liken this (p. 5). Such lucid but comprehensive prose change to “upgrades” of computer software we accurately convinces readers that H-P termi- have all had to suffer through, designed purely nology provides the only plausible way for- to make money, whereby functionality usually ward in our understanding of molts in decreases in favor of a completely unfamiliar tropical and equatorial regions. The authors look and maddeningly unnecessary changes to then adeptly apply this terminology to the keyboard strokes (for more on this subject see cycle-code system for aging birds, of which our debate in The Auk: Wolfe et al. 2014, they were instrumental in deriving, again con- Howell and Pyle 2015). Yet, I must also stress firming this classification system as the only how minor these fusses are in the overall enter- feasible one for Neotropical birds. The five prise. Collectively, it feels like we H-P adher- pages devoted to coverage of this system, ents are making steady progress in defining the along with coherent tables and effectively sim- world’s bird molts, and the authors have ple molt diagrams, is a mandatory study for greatly expanded the frontier regarding all students working on bird molt in the Neotropical species. Neotropics. The categorization strategy for The family accounts are not really bedtime the application of these codes, including eight reading, although I would recommend so for groups defined on pages 11–13, should the introductions to each chapter, where gen- become a standard for applying this system to eral descriptions include unique physical char- birds worldwide. acteristics of each family, flight-feather counts, We students of bird molt love to niggle, and and very complete and well-referenced sum- I cannot resist pointing out a couple of minor maries on molt strategies, in virtually all cases disagreements. Defining all single inserted including knowledge advancements. In many first-cycle molts under the Simple Alternate cases, these represent the first time molt has molt strategy as “first alternate” (p. 6) defeats been directly considered within a family, e.g., the intent of the H-P schema. Some, if not for Psophiidae (trumpeters), Nyctibiidae (po- many, of these molts undoubtedly evolved, at toos), Bucconidae (puffbirds), Capitonidae least in part, from preformative rather than (New World barbets), Ramphastidae (toucans), first prealternate molts of ancestral species, and Cotingidae (cotingas and allies), and Tityridae it should be up to us to figure this out, rather (tityras). These were my favorite sections, and I than homogenizing the terminology “for con- applaud the authors for including summaries venience” (“convenience,” it should be pointed for all central Amazonian families, even though out, is what disoriented traditional molt termi- little direct data were added for a few of them. nologies in the first place). Few if any The accounts for most families and species, Neotropical landbirds undergo the Simple however, were based on an extensive database Alternate Strategy, so this distinction is not of > 65,000 mist-netted birds, as part of the important here. On the other hand, the incredible Biological Dynamics of Forest Frag- authors’ redefining of the H-P term “defini- mentation Project, initiated in 1979 by Tho- tive” to apply to molt cycles rather than plu- mas Lovejoy near Manaus, Brazil, and for mages (p. 7) seems utterly unhelpful, if not which both Johnson and Wolfe completed detrimental, to our understanding of the pro- their Ph.D. research. These data were supple- cess. It appears to have been crafted to fit a mented and confirmed by the authors’ exami- few manakin species that follow unusual sex- nation of > 1000 specimens. Each account specific plumage-maturation strategies not draws extensively from this database and found among the remaining 10,000 or so includes measurements by sex, species Vol. 89, No. 1 Recent Literature 107 identification criteria, molt strategies, and age/ LITERATURE CITED sex-determination criteria. Hundreds of sharp and well-produced photographs are sprinkled DICKEY, D. R., AND A. J. VAN ROSSEM. 1938. The throughout the accounts, often including one birds of El Salvador. Zoological Series of the Field Museum of Natural History 23: 1–609. or more illustrative images per age-cycle class FOSTER, M. 1975. The overlap of molting and per species (and, yes, many are of spread wings, breeding in some tropical birds. Condor 77: 304– allowing detailed study of molt limits). The 314. captions to these photos include appropriate GUALLAR, S., E. SANTANA,S.CONTRERAS,H. VERDUGO, AND A. GALLES . 2009. Paseriformes del uncertainty, along with proposals that reflect Occidente de Mexico: morfometrıa, datacion y full consideration of every angle regarding sexado. Institut de Cultura de Barcelona, potential molt strategies within each species. Barcelona, Spain. For species with larger numbers of captures, HERNANDEZ, A. 2012. Molt patterns and age and sex the accounts include very informative bar criteria for selected landbirds of southwest Colombia. Ornitologıa Neotopical 23: 215–223. charts illustrating seasonal molt and breeding HOWELL, S. N. G., AND P. PYLE. 2015. Use of patterns from capture data, and in some cases, “definitive” and other terms in molt scatterplots or frequency distributions, based nomenclature: a response to Wolfe et al. (2014). on measurements, to help separate species or Auk 132: 365–369. LENTINO, M. 2016. Manual de anillado e sexes within monochromatic species. In sum, identificacion de las aves del Paso Portachuelo, these accounts present an incredible resource Parque Nacional Henri Pittier, Venezuela, for those taking the next steps in understanding Segunda Edicion. Sociedad Conservacionista Neoptropical bird molt, in particular, for Audubon de Venezuela, Caracas, Venezuela. resident tropical species within large and vari- PYLE, P., A. ENGILIS, Jr., AND D. A. KELT. 2015. Manual for ageing and sexing the landbirds of able families such as hummingbirds, antbirds, Bosque Fray Jorge National Park and north- ovenbirds, tyrant flycatchers, manakins, and central Chile, with notes on range and breeding tanagers. seasonality. Special Publications of the Louisiana State University, Baton Rouge, LA. At the risk of revealing the punch line of the book (spoiler alert!), a key overall finding ———,A.MCANDREWS,P.VELEZ,R.L.WILKERSON, R. B. SIEGEL, AND D. F. DESANTE. 2004. Molt is that molt patterns of Neotropical birds patterns and age and sex determination of selected share many fundamental consistencies with southeastern Cuban landbirds. Journal of Field those of better-known temperate species, both Ornithology 75: 136–145. within and among families and genera. In SNOW, D. W., AND B. K. SNOW. 1964. Breeding seasons and annual cycles of Trinidad land-birds. turn, this strongly indicates, as the authors Zoologica 49: 1–39. point out, that the information provided here TORREZ, M. A., AND W. J. ARENDT. 2016. La muda should apply to most or all of the remaining en especies de aves de Nicaragua. UCA 4000 species of Neotropical birds. For this Publicaciones, Managua, Nicaragua. WOLFE, J. D., E. I. JOHNSON, AND R. S. TERRILL. and many other reasons, I consider this an 2014. Searching for consensus in molt “absolute must” for any student of either terminology 11 years after Howell et al.’s “first avian molt or avian tropical systems, and it basic problem.” Auk 131: 371–377. has already become one of the eight or so ———,P.PYLE, AND C. J. RALPH. 2009. Breeding most critical molt-reference works within seasons, molt patterns, and gender and age criteria for selected northeastern Costa Rican resident immediate reach of my desk. landbirds. Wilson Journal of Ornithology 121: 556–567.