Birds of Central America: Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama
Andrew Vallely and Dale Dyer
Princeton University Press, 2018
Imagine that you are walking through a humid broad-leaf forest in the Panamanian Darién, completely soaked. You don’t know if your clothes are waterlogged from sweat or precipitation, but probably both. It’s been over an hour since you’ve even seen a bird, and the heat of the late morning is starting to wear on you. You’re about to sit down and enjoy a granola bar when you hear a few chip notes. In seconds the vegetation around you abounds with birds. Tanagers dart between toucanets in the canopy, antwrens and foliage-gleaners work through vine tangles, and the understory is alive with brush-finches. You drink in these creatures through your binoculars, making a mental note of every field mark, foraging maneuver, and call note. Within three minutes most of the mixed-species flock has vanished into the forest, leaving you with the task of identifying everything you just saw. Field guides exist for just this purpose: to help naturalists identify species by studying them before they actually see them, and placing their observations in the context of known biodiversity after an encounter. Birds of Central America, by Andrew Vallely and Dale Dyer, enables students of ornithology to identify the birds of Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama and think about them in the context of a regional avifauna like never before.
Creating a field guide to birds of Central America (the landmass between the Isthmus of Tehuantepec and the Darién Gap) is no easy task. Nearly 1,200 species have been documented in the region, providing prospective authors with the challenge of adequately incorporating them into a book. The vast literature on the region’s avifauna has tackled this problem in different ways. Classic texts like Stiles and Skutch’s A Field Guide to the Birds of Costa Rica (1989) and Howell and Webb’s Field Guide to the Birds of Mexico and Northern Central America (1998) treat each species they include with immense visual and descriptive detail, yet limit the geographic scope of their books to political and biogeographic subsets of the Central American avifauna. However, these books are physically cumbersome, and the separated plates and text require patience for contemporary users. Others, like Ber Van Perlo’s illustrated checklist Birds of Mexico and Central America (2006), cram sloppy illustrations with minimal information into a tiny book that’s hardly useable as a field guide or reference material.
A plethora of field guides bridge this spectrum of quality, and evade the challenge of discussing and depicting all birds in Central America by focusing on specific countries or regions. Richard Garrigues and Robert Dean’s The Birds of Costa Rica (2006) is a popular example of this middle ground. The book is fairly small, and conforms to the modern format of having the plates opposite the text and range map on a single spread. However, it only has one or two illustrations for each species, and the text about habitat and distribution is fairly abridged. These features make Garrigues and Dean very user friendly, especially for visiting tourists who may not have prior experience with tropical birds, but it lacks the oomph of top field guides, such as Sibley (2000), Svensson et al. (1999), and Jaramillo et al. (2006). Granted, the regions covered in these field guides (North America, Western Palearctic, Chile), have species that have been extensively studied for centuries, allowing for very detailed species accounts, but the last few decades have seen such a development in our understanding of field identification and life histories of Central American birds that not including such information in modern, popular literature seems like a crime.
Similar books have followed Garrigues and Dean, such as Angehr (2010), Fagan and Komar (2016), and Chavarria-Durriaux et al. (2018), which have more detailed species accounts and quite a few helpful vignettes, but remain handicapped by their recycled illustrations by Robert Dean. Dean’s illustrations are quite good, but often fall short of lifelike depictions of structure and behavior, and the extent of geographic variation in species across Central America. However, recycling illustrations enables authors to produce field guides fairly quickly—hence the slew of books featuring Dean’s work released in the last few years.
Creating and organizing new illustrations for every species in Central America is a massive undertaking, yet Valley and Dyer rose to the challenge, spending ten years in the American Museum of Natural History’s study skin collections and in the field. The payoff from this decade of work is remarkable, with all nearly 1,200 species represented.
Readers are immediately drawn to Dyer’s rich paintings, which reflect his experience as a professional illustrator and formal training as a fine artist. Rather than the crisp, hyper-realistic illustrations in Svensson et al., Dyer’s work is soft and rich. His care in creating and depicting color is top-notch, excellently capturing the subtle browns and greens of challenging groups like woodcreepers and forest flycatchers, which many tropical field guides struggle to accurately depict. Life-like shading makes his best illustrations emerge from the page in a more realistic way than Dean’s fairly flat images, and Guy Tudor’s, whose images pop because of strong highlighting rather than smartly constructed colors and shadows.
Dyer also excels at depicting birds’ postures and structure—nearly all of his perched birds have a well-defined and developed center of gravity. I especially like the antbirds, whose varying foraging niches can often be inferred from their illustration. Dot-winged Antwrens are shown crouched on thin perches, necks extended and tails cocked, enabling the reader to imagine them flouncing through a flock or probing a cluster of dead leaves. Bicolored Antbird is hunched on a vertical branch, enabling one to imagine an army ant swarm crawling below it. Perches and foraging behavior are also frequently shown: on a single plate, a Worm-eating Warbler extends its bill toward a cluster of dead leaves, and a Swainson’s Warbler has two feet firmly on the ground while an Ovenbird walks with one leg in the air. These smart depictions allow readers to imagine birds in their element before consulting the text on the opposite page, becoming familiar with a species before they encounter it in the field. Additionally, most species are represented by multiple images, painting a picture of intraspecific variation due to season, sex, polymorphism, or geography.
Having plates by a single artist contributes to the visual continuity of the book, giving it an edge over Birds of Peru (Schulenberg et al. [2007]) and Birds of North America(Dunn and Alderfer [2017]). Studying the variation in Dyer’s illustrations is a fascinating endeavor, allowing the reader to see the evolution of an artist over a decade. Some early illustrations in the book (i.e., Chlorophonias) lack the nuance of later work. Several tanagers, orioles, euphonias, and other passerines also have a slightly exaggerated hook at the tip of the bill, a feature some of Dyer’s paintings show in Birds of Peru. And while birds’ structure is usually spot on, a few groups stand out as not quite right, such as slightly rotund swifts, large-headed screech-owls (which strikes me as weird since the nightjars are exceptional), and oddly proportioned Pterodroma petrels.
In spite of a few challenging groups like seabirds and swifts being a hair off, Dyer depicts many species in flight through vignettes, illustrating pigeons and raptors particularly well. The Buteogallus plate is one of my favorites I’ve seen of the genus, showing confusing variation between similar species in a concise yet thorough way. More illustrations of birds in flight would be welcome, particularly for more passerines.
Additional vignettes augment the plates, depicting specific field marks such as tail patterns (i.e., Myiarchus and nightjars), displays (manakins, cotingas), and foraging (I love the Red-headed Barbet peering down a leaf). More vignettes and entire pages depicting birds at a distance, in bad light, and strange angles would significantly improve the quality of this guide. For example, woodcreepers are a challenging group for beginners and experts alike because they have similar plumages, and are difficult to get a good look at as they cling vertically to tree trunks, often high up or far from the observer. One vignette shows a single image of a Spot-crowned Woodcreeper from behind at a 45-degree angle, with a note on the plate about how difficult woodcreepers can be to identify in the field. An entire plate showing the eighteen species of Central American woodcreepers at this angle, and discussing the structural and plumage features that can be used to identify species given a poor look, would be groundbreaking for tropical field guides.
Composing the thousands of vignettes and “standard” illustrations into organized plates is an additional art form that the authors have given substantial thought to. They explain their methodology in the introductory text, showing drabber plumages on the left side of the plate, and brighter ones on the right. Northern subspecies are placed above southern ones, western subspecies are on the left, and eastern on the right. However, conforming to a specific format is not always practical for vastly different taxa, which have unique features that need highlighting. The additional constraints of printing logistics further influence the authors’ decision-making processes. The resulting plates vary in their format, some with twenty images (Yellow Warblers do have a lot of variation to show), and others with five (the “Cling” rail complex). More standardized arrangements would improve the book, resulting in the continuity that has contributed to the success of books like Sibley (2000) and Svensson et al. (1999). Whether dense or sparse, all species on a given plate are shown to scale, with the scale-percentage printed in the upper right-hand corner.
The book’s text is as worthy of praise as its illustrations are. Vallely excels at conveying complex and detailed information concisely. As the plates are, the species accounts are well organized. They begin with a broad description of the birds’ global range, thereby providing context to the variation addressed within Central America. Distributions within Central America are very well described, with up to four sentences reviewing the species’ status within the major habitat types and biogeographic regions outlined in the introduction. Citations in the status and distribution section are nice to see, referring readers to more detailed discussions of occurrence in the published literature. Elevational distributions are also provided for most species for which they are relevant, which makes a handy quick reference for similar parapatric species. Microhabitat use is described in the “habits” section, with descriptions of behavior that aid in identification and inform the reader on the species’ ecology and life history. Field marks are described succinctly and accurately, with the most important features italicized. Structure and flight style are also adequately discussed, though not necessarily consistently across families. Another inconsistency in the species text is the lengths of birds, shown on the upper-right of the account. Most species have a single measurement listed, though a range of lengths is given for a few. Fortunately, different lengths are provided for species with strong sexual dimorphism. It would have been nice for the authors to include additional morphological metrics, such as wingspan and mass. The space between the species’ Latin name and the margin seems to allow for this.
Descriptions of vocalizations and other sounds are also well done, with transliterations of the sound modified by descriptions of syntax and pitch. Multiple types of songs and calls are described for each species, and often compared to similar sounds made by different species. This is quite welcomed, as the majority of field guides fail to make this very useful comparison.
The introductory material is also well written, outlining the objectives of the book and explaining the authors’ methodology and decision-making process. Good additions to this section are two neat tables, one defining species status terms (common, uncommon, etc.), and the other describing the habitats later used in the species accounts. Six pages are dedicated to discussing the biogeography of Central America, entailing a quick summary of a region: where it’s located, a description of its contemporary vegetation, what representative bird species live there, and even a bit of geologic history. These summaries provide context for the diversity of birds in the book, and help teach readers how to think critically about habitat and distribution.
Large political and topographic maps in the introduction also help readers visualize the biogeographic patterns discussed, and provide a reference for the smaller maps in the species accounts. Depicting species distributions in field guides is particularly challenging in the Neotropics, where ranges are often confined to specific elevations and tiny valleys—features difficult to show well on a small map. Furthermore, much remains to be learned about bird occurrence, with new records and range expansions constantly being discovered. To account for these nuances, the authors use four different symbols to depict localized populations, vagrants, historic records, and uncertain distribution. These symbols complement the coarser range maps that are color coded by seasonality. One could complain that these maps are too coarse, and don’t reflect the actual distribution of the species and the habitats it occupies. Several maps in Fagan and Komar (2016) used GIS to produce very fine-scale maps of specific habitats (i.e., Pine-Oak forest for Ocellated Quail), but it can often be difficult for a reader to know exactly where they are in relation to the small, pink squiggles, which may not make the extra work to create these tiny, intricate figures. Preparing the reader to assess habitat and think about biogeography relative to their location is arguably more important.
Other helpful features in the book include an index for the families on the jacket flaps, an annotated list of “marginal, dubious, and hypothetical” species, and notes about taxonomy. The book closes with an extensive bibliography of over 600 references, further reflecting the decade’s worth of homework the authors have done.
The wealth of information described above fits nicely into a book that is on the larger and heavier end of a field guide. It weighs in at three pounds, and measures slightly shorter and not as wide as the big Sibley (2000), but is a hair thicker. While it is admittedly cumbersome relative to the smaller country guides illustrated by Robert Dean, it is a feather for those used to schlepping Howell and Webb (1999) or Hilty and Brown (1986). Readers who are concerned about weight may prefer the Dean series for carrying in the field, but anybody living in or preparing for a trip to Central America would be cheating themselves if they did not prioritize Vallely and Dyer for consultation.
Another logistical consideration is the digital media currently available to aid field identification. Several apps of varying quality have been released on the birds of Central America, though they are admittedly focused on Costa Rica and Panama. The Cornell Lab of Ornithology’s app “Merlin” is also an excellent option, now offering a paragraph of identification and natural history information, range maps, photos, and recordings for virtually all of the species in Central America, available for free. These apps make great supplements to big field guides. Valley and Dyer is also available for Kindle, making it more portable. I have not reviewed the Kindle edition, so cannot comment on how the digital format affects its utility.
All things considered, Vallely and Dyer is a must for any amateur or professional tropical bird enthusiast. The book demonstrates the payoff of ten years of hard work by two dedicated authors, ranking alongside the field guides to the birds of Peru (Schulenberg et al. [2007]) and New Guinea (Pratt and Beehler) as the best representations of a tropical avifauna. Aside from at least one minor typo (the range maps for Blue-throated and Turquoise-browed Motmots are switched), the only things that would make it a better field guide would be more vignettes and identification discussions of difficult families and field scenarios, and slightly more standardized arrangements of illustrations on the plate. I also look forward to seeing an edition in Spanish. Whether or not you live Central America or will be traveling there, perusing Vallely and Dyer is like taking a trip there yourself. Look a little harder and you can almost taste the mossy cloud forest air.
Jacob Drucker
Victor Emmanuel Nature Tours
January 2019