Antpittas and Gnateaters

Harold Greeney, originally an entomologist, first became aware of the allure of antpittas and gnateaters whilst working in Ecuador some 20 years ago, and subsequently converted to birding and ornithology. Drawn initially by an interest in finding the nests of antpittas, Greeney quickly became an expert in this field, documenting the nests and breeding biology of several species of antpitta for the first time. Evidently, he has spent an enormous amount of his time and energy, over a period of many years, studying these two amazing families of Neotropical suboscine passerine. This has culminated in the publication of an incredibly detailed and inspiring Antpittas and Gnateaters, two groups of bird that most birders are drawn to on any visit to the Neotropics, and indeed, are usually among the highlights of any Neotropical birding trip.

This book is a rather unconventional monograph when compared to others in the Helm Identification Guide Series, or indeed, when compared to similar books by other publishers. Usually, bird family monographs of this nature have quite significant introductory sections that give an overview of the birds that are included, but in this case, Greeney skips this entirely and the book starts with a section entitled Layout of the Book. Hence, there is no section summarizing any of the normal topics that we have grown to expect, such as evolution, relationships, taxonomy, distribution, breeding biology, conservation, etc. Instead, all of this information is provided on a species-by-species basis, so if you want to learn something about the antpittas or gnateaters as a group, or to put any of their relationships, behavioural traits and so forth into a global or Neotropical context, you will need to look elsewhere, most likely to HBW (del Hoyo et al. 2003). Nevertheless, this heavy tome is a remarkable piece of work, containing a huge amount of new or obscure information on these two bird groups, with an emphasis on breeding biology and, to a lesser extent, attempting to document every locality where each taxon has been recorded.

As mentioned above, the first part of the book is a useful section on using this guide. It contains a well-written explanation of the rationale and methods used to write the various sections in the species accounts, which form the bulk of the book. This chapter on Layout is immediately followed by the illustrations. The 24 plates of illustrations by David Beadle (although not mentioned in the acknowledgments) are beautifully executed and depict the jizz of these unobtrusive, mostly forest denizens very accurately. The plates illustrate between two and five species, often including immature and juvenile plumages, as well as some of the subspecies. Greeney is also an accomplished artist, and there are four black-and-white illustrations depicting nesting behaviour in the introductory part of the book.

Antpittas and Gnateaters covers 64 species in six genera and two families: eleven species of Gnateater (including two species of Pittasoma) and 53 species of Antpittas. The Species Accounts vary greatly in length, with the shortest being a mere two pages for the very poorly-known Alta Floresta Antpitta Hylopezus whittakeri, but with up to 13 pages for those that are well documented, such as Thrush-like Antpitta Myrmothera campanisona. Each species account includes subsections that deal with Identification, Distribution, Habitat, Voice, Natural History, Diet, Reproduction, a Technical Description, Taxonomy and Variation, Status, and Other Names. There is a clear emphasis on sections that Greeney is most interested in, most notably Natural History and Reproduction, along with the very long lists of locations (including geographical coordinates) where each taxon has been recorded within the Taxonomy and Variation section. There are also long lists of localities where “protected populations” occur under the Status section, even for species that are not threatened. Furthermore, there are also long paragraphs with measurements of body length, wing length, and bare-parts measurements as well as body mass in a section called Morphometric Data. This all means that a significant proportion of this hefty book is taken up with lists of places with coordinates and biometric data, which makes the text rather laborious to go through. It would probably have been much better to have listed all the site locations in an Appendix at the back of the book, and perhaps the morphometric data too.

Numerous photographers have contributed almost 250 colour photographs which are included in the Species Accounts, many of which are of very high quality. These depict both the birds themselves as well as their nests, eggs, and fledglings in many instances. In keeping with Greeney’s main interest, in some cases there are more photos of the nests and eggs than of the birds themselves; for example, Ash-throated Gnateater Conopophaga peruviana has one photo of a female but none of a male, yet there are four photos depicting nesting. Slaty Gnateater C. ardesiaca has a photo of an adult male and three of nests, eggs, and nestlings. This is not a criticism, since such behavioural photos increase the value of the book. Many of the excellent nest, egg, and nestling photos were taken by Greeney. The book also includes the first photo ever taken of the restricted-range Tachira Antpitta Grallaria chthonia. Some species of antpitta are very poorly documented, and there is only one photo of a partially-hidden Ochre-striped Antpitta Grallaria dignissima, and its closest relative, the aptly named Elusive Antpitta G. eludens – as well as Grey-naped Antpitta G. griseonucha – have only a single photo of a specimen.

Not only are there no photos of these two last-mentioned species, but their nests, eggs, and breeding behaviour are completely unknown. Indeed, the nest and eggs of about a third of the species included in this book remain undocumented, despite the bests efforts of Greeney and others. Even for species for which nests and eggs are described, such descriptions are often based on only one or two discoveries. The nest of Rufous-faced Antpitta is only known from captivity, whilst the egg of Hooded Antpitta is only known from a fully-shelled egg removed from a specimen, whilst its nest is still unknown. One of Greeneys’ stated objectives was to not only document what is known about antpittas and gnateaters, but also to highlight what we don’t know, and the paucity of knowledge on many aspects of these species’ biology and even distribution is glaring when one examines this book in detail. So if you do come across the nests of any of the antpittas and gnateaters, it is well-worth documenting your observations with good photos and notes.

For the most part, the various sections of the Species Accounts are meticulous and very readable (except of course for the long lists of locations and morphometrics). Nevertheless, it seems odd that the voice descriptions have not been detailed in any standard way. Instead, Greeney primarily relies on reiterating the descriptions provided in various publications. With the availability of digital recordings online, it would have been possible for the author to have made his own comparisons between species and subspecies in a standard way, but perhaps this is something that the author is not particularly interested in (and perhaps more to the point, it is very time consuming). The same can be said for the “Technical Descriptions”, which are detailed descriptions of plumage and bare parts most often based on the work of (numerous) other authors.

Distribution maps are included within the Species Accounts. These are very detailed, with the distribution of each subspecies clearly defined, but the lack of any topographical features on the maps, apart from rivers, means that this detail is hard to visualize. This seems an odd oversight given the painstaking approach that Greeney has taken with detailing geographic coordinates. Note that there is a very useful map in the Layout section that shows the location of the major rivers mentioned in the text. In relation to distribution, Greeney has made use of eBird to identify certain sites that contain some of the species included in the book. Although I have not made any kind of analysis concerning which records these eBird sightings are based on, it should be noted that eBird sightings cannot easily be independently verified unless accompanied by a sound recording or photograph and are therefore not always entirely reliable. In contrast, sound recordings from the Xeno-canto or the Macaulay Library websites can be more easily verified but do not seem to have been put to such use in this book.

The taxonomic information in the book comes nearer the end of the Species Accounts, perhaps because the author was less concerned with taxonomy and relationships than with natural history and reproduction. Whilst the species accounts section on Gnateaters starts with a large heading entitled Family Conopophagidae, there is no such heading at the beginning of the species accounts for Antpittas, so one might be forgiven for thinking that they too are in the family Conopophagidae, rather than in a separate family, the Grallariidae, which is not mentioned. In fact, the two species of Pittasoma (named as Black-crowned and Rufous-crowned Antpitta in this book) are in fact presently treated as members of the Conopophagidae, rather than Grallariidae, so calling them Antpittas is a bit of a misnomer, and I prefer the English names adopted in some other recent publications and lists – Black-crowned and Rufous-crowned Pittasoma.

Avian taxonomy is going through an era of splitting, grounded in advancements in genetics and the availability of digital sound recordings, and any book published at this time is likely to differ in some ways from recently published taxonomies. Based on voice and morphology, Rusty-breasted Antpitta Grallaricula ferrugineipectus of Colombia and Venezuela is clearly a different species to Rufous-breasted Antpitta G. leymebambae of Ecuador to Bolivia and is treated as such by del Hoyo and Collar in the HBW Illustrated Checklist of the Birds of the World (2016), but they remain lumped in this book. Del Hoyo and Collar also recognize Western Tawny Antpitta Grallaria quitensis, Northern Tawny Antpitta G. alticola, and Southern Tawny Antpitta G. atuensis as separate species whereas Greeney treats these all as Tawny Antpitta G. quitensis, and indeed does not even illustrate atuensis even though he says “I tend to agree with this split”. Greeney states that he is maintaining them as a single species until a “more rigorous analysis” is done, yet he splits Spotted Antpitta Hylopezus macularius into three species – Spotted H. macularius, Alta Floresta Antpitta H. whittakeri, and Snethlage’s Antpitta H. paraensis – which according to the HBW Checklist have minor or non-existent differences in morphology and generally minor differences in voice. Needless to say, del Hoyo and Collar lump these three species.

Clearly, the taxonomic status of some of the antpittas is not yet fully resolved, and there are likely to be new species of antpitta recognized in the not-too-distant future, most notably perhaps in the Rufous Antpitta Grallaria rufula complex, which seems to be comprised of around six very similar-looking species. There is also a newly-discovered taxon of Grallaricula near Cali in Colombia that is probably a new species. It is somewhat similar to Peruvian Antpitta G. peruviana in appearance but apparently more closely related to Hooded Antpitta G. cucullata.

The end of the book contains an extensive bibliography (48 pages) and a good index. But whilst there is a list of acronyms at the front of the book, there is no glossary, which would have been useful for those unfamiliar with some of the scientific terms used in this book.

Overall, Antpittas and Gnateaters makes a major contribution to Neotropical ornithology and both the author, Harold Greeney, and artist, David Beadle, have produced a very impressive piece of work. Although this book is part of the Helm Identification Guide series, it is clearly not a book that you would want to take into the field on any trip, but rather a very detailed synthesis of what is known about antpittas and gnateaters. It is the work of someone who is clearly incredibly enthusiastic about his subject of interest, the breeding biology of a small subset of Neotropical birds, and as such it is particularly focused on this subject. Hence, it is not a book that the majority of birders are likely to want to buy. It is, however, a very useful reference book for ornithologists and birders who are particularly interested in Neotropical birds or avian breeding biology. I certainly learnt a considerable amount from dipping into the Species Accounts whilst undertaking this review.

– Reviewed by Frank Lambert

References:

Del Hoyo, J., Elliott, A. and Christie, D. (eds). 2003. Handbook of the Birds of the World Volume 8: Broadbills to Tapaculos. Lynx Edicions, Barcelona.