Identification Guide to North American Birds, Part I (Second Edition). Peter Pyle. 2022. Slate Creek Press, Point Reyes Station, CA, USA. 689 pages. ISBN 9780961894054. Paperback ($80).
For more than three decades, the “Pyle Guide” has been banders’ most comprehensive resource to aid in identifying, ageing, and sexing birds in the hand, and many banders consider their equipment incomplete without a copy. Part 1 of the Identification Guide to North American Birds, first published in 1997, contains meticulously detailed species accounts for all North American passerines and near-passerines with text describing all plumages, molt strategies and timing, and other identification, ageing, and sexing criteria. Each species account is systematically written and includes standardized information used for every species covered in the book, with a header that includes common and scientific names and their alpha codes, the species number, and typical band sizes used for that species. A list of species reported to hybridize with the focal species, references for further reading, and a bar graph that illustrates the reliability of ageing or sexing an individual within a given month accompanies each account. Additionally, each account includes the following sections of descriptive text: Species describes how to separate very similar species in the hand; Geographic Variation lists and describes recognized subspecies; Molt gives information about the extent, timing, and location of each molt that a species undergoes; Skull gives the date at which the first hatch-year birds can show complete skull pneumatization and provides other pneumatization timing information; Age provides a description of characteristics of plumage and soft parts that can be used as a synthesis to assign an age class; and Sex provides information about whether a species can be sexed and what characteristics are useful in sex determination. These accounts are accompanied by tables and figures that help banders visualize plumage and other descriptions within the text, and measurements that can help separate species, sex classes, and age classes.
Since 1997, there have been several updates to molt and plumage terminology, and banders have discovered and published new ways to age and sex birds. Developments in digital photography and online sharing of images made photos of molt limits, spread wings, and plumages widely accessible, and intensive study of museum specimens and extensive hands-on experience advanced our understanding of ageing and sexing birds enough that an update to the Pyle Guide became necessary. Incorporating feedback to the first edition from hundreds of banders and recent advances in our understanding of molt cycles, the much-anticipated second edition to the Pyle Guide, Part 1 was published in late 2022.
The second edition includes many changes, but perhaps most notably, and most eagerly anticipated, the molt and plumage terminology has been updated from the Humphrey-Parkes (hereafter HP; Humphrey and Parkes 1959) system to Humphrey-Parkes-Howell (hereafter HPH; Howell et al. 2003), and the new molt cycle terminology (hereafter WRP; Wolfe et al. 2010) has been added to the Age section of each species account. Briefly, the HP system referred to the molt out of juvenile plumage as first prebasic molt. In most passerines and near-passerines this is a molt that is less than complete and occurs shortly after fledging, replacing some juvenile feathers with higher quality plumage. It is not homologous with the definitive or adult prebasic molt, which is a molt that is consistent across most species, and, for passerines and some other species, is an annual restorative and complete replacement of all feathers. In HPH molt terminology, the so-called 1st PB molt has been redefined as “preformative molt” and the resulting plumage as “formative plumage.” The second edition uses this updated terminology. The HP and HPH systems are calendar-based and are familiar to most banders, but have utility only for temperate or boreal-breeding species that have molting events energetically constrained by breeding and migration. The molt-cycle, or WRP, ageing system uses codes representing a bird’s molt cycle and plumage, which has a global utility, and importantly can be used equally well in the tropics as in higher latitudes. Species accounts have been updated to include the most recent molt terminology language, and presents both calendar-year and molt cycle based ageing systems. These updates make the guide accessible to everyone and provides the opportunity for banders to develop proficiency in both ageing systems.
In the first edition, age and sex descriptions were split into sections for basic plumage and alternate plumage, where applicable. There is a noticeable organizational update to the Age and Sex sections in the second edition. The descriptions of alternate plumage are included with descriptions of non-breeding plumage (i.e., formative or basic) within the appropriate age and sex category. The Sex section often now includes a reference to new tables containing morphological measurements (wing, tail, exposed culmen, and tarsus length) that can assist with identification and sexing. Additionally, the Age section now includes the molt strategy and a list of the possible WRP codes for that species along with corresponding months when banders would expect to capture birds in those age categories. The concept of molt clines was introduced in the update as an additional characteristic to identify non-juvenile plumage.
Other changes focus on species-specific updates, reorganization, and new and revised tables and figures that provide easier reference and comparison. The section describing molt in woodpeckers was improved to more thoroughly explain the complicated molt patterns in this family. The accounts for some closely related species have been grouped together if they have similar molt strategies and ageing or sexing methods; this was done to “eliminate repetitious information.” Several new species were added including naturalized species such as parrots, parakeets, bulbuls, and munias, and species recently discovered to breed along the southern border of the United States. Lastly, taxonomy has been updated to reflect the most current order (Chesser et al. 2022).
The second edition provides a thorough discussion of molt terminology, sequence, relative extent and timing, and variability. However, it is not a photographic or otherwise illustrated guide. The text provides descriptions of features within species, but not between species (e.g. tapered vs. broad, fresh vs. relatively abraded) and these relative words vary considerably in different species. The difficulty for beginners is interpreting these words in new species and learning whether these differences are subtle or obvious among individuals of the same species and between species. The figures and line drawings are well done and provide introductory context to ageing and sexing techniques, so that beginner banders can develop their skills with practice and considerable hands-on experience. The guide is most useful when it is used in conjunction with photographic resources or under the mentorship of experienced banders using live birds.
The addition of molt cycle ageing codes to the new Pyle Guide does not extend to the bar graphs, which are presented in calendar year ageing terminology only. The molt cycle code assignments and their corresponding months are included within the text of the Age section of each species account, which may be difficult to untangle for many beginner-level banders. However, including these codes in the bar charts could make them difficult to read or interpret.
Many banders I have spoken with and I expected that discussion of alula molt limits would be added to the second edition, however, the update lacks information about molt limits within the alula feather tract or between the carpal covert and alula feathers, a molt strategy well-known to result from preformative molt in nearly all warblers, many vireos and sparrows, and other species. Although molt limits on this part of the wing can be difficult to see in closed-wing museum specimens, this strategy has been documented in banding literature (e.g. Mulvihill 1993) and photographically. Regardless of the naming convention for the alula feathers, the top alula (e.g. alula covert or “A1”) was not included in the bird topography illustration and is not referenced in relevant species accounts. The second edition indicates that the greater alula can be replaced during preformative molt in many species that almost never, or at best atypically, replace the lesser and greater alula feathers (e.g. warblers).
In the first edition, Pyle’s “a call to banders” solicited banders to provide “contradicting, additional, or supporting information” so that our collective understanding of identification, ageing, and sexing techniques for North American birds is as detailed as possible. Banders by the hundreds answered this call and Pyle integrated that information into the second edition. Just as in the first edition, the second edition encourages banders to contribute their knowledge and discoveries to ornithological publications, and banders should continue to monitor recent literature for new information. The seamless incorporation of molt cycle terminology into each species account is this guide’s greatest strength, making it accessible to all banders, which is useful in transitioning between the calendar-year and molt cycle systems and enhances communication among banders throughout the western hemisphere. This comprehensive guide provides the most up-to-date information in ageing and sexing North American passerines and near passerines so that data collection will be more accurate and standardized. The first edition proved to be an excellent and unique resource, and The Identification Guide to North American Birds, Part 1, Second Edition follows suit: it is a thorough tool for those who capture and band North American passerines and near passerines, and ornithologists will no doubt find the updated edition to be instrumental in their studies.
Andrea M. Lindsay
Powdermill Avian Research Center
Carnegie Museum of Natural History
- Chesser, R.T., S.M. Billerman, K.J. Burns, C. Cicero, J.L. Dunn, B.E. Hernández-Baños, R.A. Jiménez, A.W. Kratter, N.A. Mason, P.C. Rasmussen, J.V. Remsen, Jr., D.F. Stotz, and K. Winker. 2022. Sixty-third supplement to the American Ornithological Society’s Checklist of North American Birds. Ornithology 139: https://doi.org/10.1093/ornithology/ukac020.
- Howell, S.N.G, C. Corben, P. Pyle, and D.I. Rogers. 2003. The first basic problem: A review of molt and plumage homologies. Condor 105:365-369.
- Humphrey, P.S., and K.C. Parkes. 1959. An approach to the study of molts and plumages. Auk 76:1-31.
- Mulvihill, R.S. 1993. Using wing molt to age passerines. North American Bird Bander 18:1-10.
- Wolfe, J.D., T.B. Ryder, and P. Pyle. 2010. Using molt cycles to categorize the age of tropical birds: An integrative system. Journal of Field Ornithology 81:186-194.
Header photo: Rose-breasted Grosbeak (Pheucticus ludovicianus), Powdermill Nature Reserve | Carnegie Museum of Natural History
The Second Edition of The Identification Guide to North American Birds, Part I is also available at Avinet Research Supplies HERE.
Lindsay, A. 2023. Review of the book Identification Guide to North American Birds, Part I, Second Edition. Association of Field Ornithologists Book Review, https://afonet.org/2023/03/identification-guide-to-north-american-birds-part-i-second-edition/.
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