Wednesday, 26 August 2020

Britain's Ferns: A field guide to the clubmosses, quillworts, horsetails and ferns of Great Britain and Ireland

Britain's Ferns: A field guide to the clubmosses, quillworts, horsetails and ferns of Great Britain and Ireland

James Merryweather
Princeton University Press WILDGuides | 2020
280 pp. | 15 x 21 cm
Paperback | £20 / $ 23.95 | ISBN: 9780691180397

Ferns are – at least to this novice – a rather daunting identification prospect, notwithstanding the manageably low diversity compared with more popular taxonomic groups. My first attempt to get to grips with ferns was in the early 1980s, enthused by the newly published Grasses, ferns, mosses and lichens of Great Britain and Ireland, one of several ground-breaking Roger Phillips guides published by Pan (of which his Mushrooms has best stood the test of time). This was quickly supplemented by the Collins guide to the grasses, sedges, rushes and ferns of Britain and Northern Europe, from another proven field guide pedigree. As I take them off the shelf now, these pioneering aids look decidedly dated, and perhaps I can be pardoned for blaming my lack of expertise to some extent on deficiencies in the literature. In the intervening period (while I lived outside the UK), Page’s excellent The ferns of Britain and Ireland, has become the standard work, although since it is seemingly never to be found second hand for less than £60 I am not in a position to have acquired it. So I lay out my cards as an interested – and probably not very persevering – novice, and my assessment of the current guide should be taken as such.

But there’s no excuse for not tackling this group now. James Merryweather’s new field guide should put British fern identification within the reach of the most botanically (and economically) challenged. It is small, portable, clear and up-to-date. All 60 native ferns, 6 clubmosses, 3 quillworts and 9 horsetails are treated in this new photographic guide, in a format that will be very familiar to aficionados of the growing WILDGuides series.

Like most WILDGuides books, the aim is not merely teach the user the characters of each species, but primarily to inculcate an identification process that can be applied to any specimen encountered. As with companion guides, the introductory sections – a full 97 pages – comprise identification procedures, extremely detailed keys, and a guide to families. Those allergic to keys should not be put off, since this highly visual resource bears little resemblance to the dry dichotomous texts of yore. Here text, photographs, diagrams and clever design are married to produce a tool that the least technically proficient will be able to use. So the recommended way to use the guide is to work through the keys to find a suggested identification, which then directs the user to a full species description.

The species descriptions each cover a double-page spread, with most of the text, a map and a full-plant photograph appearing on the left, complemented by large photographs of fronds, sporangia and further detail on the right. These are very straightforward to peruse. Additional tables are provided to aid critical identification of the tricky British male-ferns. The closing pages are largely devoted to guidance as to when and where to encounter ferns and to further resources for study and recording. The skill of designer Rob Still is everywhere apparent, making the material supremely accessible.

The text itself is remarkably free from technical terms, so can be used with ease by the complete beginner. Indeed, the warm, accessible, occasionally whimsical style, is ideally suited to the task. However, the amount of information provided will make it just as handy for experienced botanists or professional ecologists. The author has decades of experience in the field and has already produced a previous illustrated key in the popular Field Studies Council AIDGAP series.

This is yet another ground-breaking WILDGuides initiative: as the first portable photographic field guide to British ferns, it really plugs a gap in the British identification literature. As usual, I can find little to fault here, and no reason why any keen naturalist would not want to get hold of a copy. I would expect to see interest in this group increase in response, as has occurred with the emergence of previous novel guides, to the benefit of national recording schemes. This can only be good for conservation, which is one of the major aims of the WILDGuides founders. Grasses next?


Fitter, A., Fitter, R. & Farrer, A. (1984) Collins guide to the grasses, sedges, rushes and ferns of Britain and Northern Europe. Collins, London.

Merryweather, J. (2007) The fern guide. 3rd edition. Field Studies Council, Shrewsbury.

Page, C.N. (1997) The ferns of Britain and Ireland. 2nd edition. Cambridge University Press.

Phillips, R. (1980) Grasses, ferns, mosses and lichens of Great Britain and Ireland. Pan, London.

Phillips, R. (1981) Mushrooms and other fungi of Great Britain and Europe. Pan, London.

Rose, F. (1989) Colour identification guide to the grasses, sedges, rushes and ferns of the British Isles and north-western Europe. Viking, London.

Wednesday, 10 June 2020

Book review: Britain’s Birds. An Identification Guide to the Birds of Great Britain and Ireland. Second Edition

Britain’s Birds. An Identification Guide to the Birds of Great Britain and Ireland. Second Edition, fully revised and updated

Rob Hume, Robert Still, Andy Swash, Hugh Harrop & David Tipling
Princeton University Press WILDGuides | 2020
576 pp. | 15 x 21 cm
Paperback | £20 / $ 35 | ISBN: 9780691199795

Despite commencing birding at a time when painted plates in field guides left quite a lot to be desired, I have been slow to entirely embrace photographic guides. My first was the Collins Bird Guide, “a revolutionary field guide” to the birds of Britain and Europe, and it provided a welcome additional source of visual material at a time when good quality photographs of birds were not readily available, but I certainly never pressed it into action as a field guide. The first publishers that seemed to be dealing with the limitations of photographic material in order to take full advantage of growing photographic libraries were WILDGuides in the UK and Kenn Kaufmann in the USA. Both were skilfully manipulating selected images in order to compensate for different light conditions, standardise postures and eliminate artefacts of the photographic process. Both publishers now have a long list of titles covering a wide range of taxonomic groups, some of which have were sorely lacking in identification literature, and many of these guides are now standard identification works. However, the United Kingdom’s avifauna is very well covered by a dizzying number of field guides, some of them amongst the best guides to any avifauna in the world. A new guide launched onto this crowded field has to be very good indeed if it is to make any significant contribution. And Britain’s Birds, published in 2016, is, and it has.

I have had the first edition by my bedside since that time. I typically pick it up at the end of the day to resolve queries arising from the day’s encounters, and one consultation generally leads on to another. After 40+ years of birding, I still get puzzled or excited by something every day, and this book helps me resolve doubts. It seems fitting that the first author, Rob Hume, has been a familiar name from YOC/RSPB magazines since I began birding. Rob’s co-authors together have truly formidable experience, not only on this topic, but in photography, design and the production of field guides. So the user is in very safe hands indeed.

Britain’s Birds is a large, comprehensive field guide, approaching the size of many of the standard Neotropical guides that cover avifaunas several times as large. At 1.44 kg and nearly 600 pages, it could be reasonably argued that this is not a field guide at all – indeed, my first edition has never seen sun, shower or the shady inside of a backpack – but then again, British birders of my generation were schooled to leave all references at home, but rather to take detailed field notes, something that I dutifully abide by to this day; and indeed, being of a similar vintage, this is the process suggested by the authors.For those who feel daunted by such a tome, or really do want a portable guide to take into the field, watch out for my review of the companion British Birds, A Pocket guide.

Why so large? The authors cover all 631 species on the British and Irish lists as of the end of 2019, using BOU/IRBC taxonomy which is in turn adopted from the IOC World Bird List (note that, as Nigel Collar has pointed out, IOC denotes the “international ornithological community”, not International Ornithological Congress). Another 33 species are also covered. So a page per species is about what one would expect for a visual guide to birds.

A typical species account
What about content? All regularly occurring species are typically treated by a page of coverage which includes text, photographs and a map. Birds are presented in their habitat, giving an additional clue to their characteristics. Scarcer species receive less space, while problematic groups, such as gulls, enjoy expanded comparative sections. All plumages are included, depicted with 3,591 photographs.

Maps are derived from current BirdLife International base maps, which were originally compiled by BirdLife International and Handbook of the Birds of the World (the latter now defunct). They are a generous size that is easy on the eye and permits high resolution. Arrows indicate broad migration routes. Status, seasonality and population data appear above the map, and habitat information below, allowing the user to determine almost at a glance the chances that a particular species has been seen.

Text is concise and, for me, achieves that tricky balance between providing enough description to clinch identification and avoiding extraneous detail. The team’s field experience is much in evidence, with expert insight being employed to craft succinct accounts that incorporate much distilled identification knowledge. Capitals, bold text and italics help navigate the sections.

Any downside? Having written field guides myself, I have renewed respect for those who take on such a task, and am now strangely reluctant to pick holes in the work of others. The production of a work like this is a massive undertaking, and all field guides contain errors, many of them spotted the day after the galleys go to press. However, I would be hard pressed to find much to complain about with this field guide, and remarkably uncharitable to draw attention to anything I found. I had already consulted the first edition on a daily basis, and – barring one unfortunate but conspicuous photo mix-up in my first printing – errors were few and far between, and the overall utility of the guide simply swamps any gripes. This edition has corrected the few oversights I had found and has improved the already high overall quality in every respect. Doubtless Chris Batty’s role as an identification consultant will have eased the burden of verification (he kindly gave me the benefit of his formidable knowledge on one of my own field guides). As far as field guides to the British avifauna are concerned, Svensson et al.’s Collins field guide and this current volume have, for me, become the two standard works the I reach for first, and their very different approaches complement each other nicely. If I need to delve beyond them, I reach for Witherby, BWP, van Duivendijk, Beaman and Madge, Harris et al. or the relevant standard monograph.

Given that I view this as a must-have for anyone with an interest in identifying the birds of the UK, whatever their level of expertise, the question then becomes, “Should owners of the first edition replace it with the second?”. That’s a hard question to answer, and depends as much on the strength of one’s bookcase shelves and the tolerance of one’s cohabitants as any technical factors. The current edition incorporates 800+ new photos, layout has been improved in key places and the entire production looks to have been revised with a fine tooth comb. And, of course, the list of taxa covered is bang up to date, reflecting the February 51st BOURC Report. So American ‘Taiga’ Merlin (columbarius) and Shorelark (alpestris group) are covered, as are other splits and additions over the past four years.

This is yet another ground-breaking field guide from the WILDGuides imprint, and an outstanding guide to Britain's birds for observers of all levels. At a retail price of £20, this is an absolute bargain. The authors and all contributors are to be heartily congratulated.


A typical double-spread species account, in this case for Dunlin Calidris alpina, showing the major plumages encountered in Britain and Ireland, along with subspecific variation. This is a variable species, and a standard, common 'yardstick' shorebird, so the coverage will be useful for beginners as well as those who want try to determine which subspecies they are seeing. Note the map indicating migration routes, and table showing the months during which different subspecies may be encountered. All relevant information can be taken in at a glance.

The double-spread devoted to the White/Pied Wagtail Motacilla alba complex has been completely overhauled in this edition. I still find alba hard to clinch, despite having read and re-read all of the literature, coupled with hours spent staring in monochrome at borderline individuals, so have already interrogated these pages several times. Photographs have been selected to help people like me. Note the inclusion of personata, new to Britain since the book's first edition.

Ducks in flight: handy double-spread guide to fieldmarks. The images are first class, and the spread has been slightly improved since the first edition, with subtle eye-guiding lines linking images of the same species. Similar comparison spreads are provided for other groups that requite critical flight identification, for example gulls, shorebirds, raptors – even larks.

Particularly tricky identification challenges are sometimes addressed by means of an extra page or two, in this case examining the similar Apricaria golden plovers. Not quite as much has been made of differences in leg length/proportion and head pattern as I might have suggested, but nevertheless the key identification characters are well covered.

Saturday, 23 November 2019

Book review: two new guides to the birds of Colombia

Field Guide to the Birds of Colombia
Miles McMullan
Rey Naranjo (Bogotá) | 2018
432 pp. | >5,000 colour figures, maps.
Softback | £49.99 / $65 / $115,000 COP | ISBN 978-9588969626

Guía ilustrada de la avifauna colombiana
Fernando Ayerbe Quiñones
Wildlife Conservation Society (Bogotá) | 2018
410 pp. | 212 colour plates, 1,932 maps.
Softback | $120,000 COP (apparently unavailable outside Colombia) | ISBN 978-9585461031

Just finished my review of two exciting new guides to the birds of Colombia, to be published in Neotropical Birding 26...


Wednesday, 12 June 2019

Orchids on Chapel Green wildflower meadow, Rocklands

Flower-rich meadow with orchids, Chapel Green, 12 June 2019
After an apparent absence of several years⁠—though these things can be notoriously elusive!⁠—Bee Ophrys apifera and Common Spotted-orchid Dactylorhiza fuchsii are coming into flower on Chapel Green. In previous years the best area for these orchids has been the southern edge of the meadow adjoining the road, the spot that is driest and has lowest fertility thanks to years of removal of hay. This year, the orchids are close to the pond margin in a much wetter, more fertile area (see photo) that we have been managing precisely to increase floral diversity. This morning there was one flowering spike of Bee and two of Common Spotted-orchid.

Bee Orchid Ophrys apifera

Common Spotted-orchid Dactylorhiza fuchsii

Update 30 June 2019

Today's count 1 Bee and 7 Common Spotted-orchids.

Update 7 July 2019

Today's count 1 Bee and 9 Common Spotted-orchids.


Monday, 10 June 2019

Ghost Moth lek on Rocklands' Chapel Green

Ghost Moths Hepialus humuli are one of the few British moths that have entered popular culture and are—or used to be—generally known to the non-specialist.  In earlier times, when insects were more abundant, meadows more commonplace, street lighting less widespread, and people abroad in the gloaming, an encounter with this species would have been a frequent early summer occurrence. Frequent but nevertheless remarkable. The memorable sight of a dozen or more large white moths hovering over the grass tops as if tethered to a thread in the fading light doubtless gave rise to their name.

Today this sight is considerably less familiar. In fact, unless they make a special effort, even moth-ers have rarely seen it. So when keen moth-man and wildlife writer James Lowen asked if anyone in East Anglia knew of a lek to cover in his forthcoming book, I racked my brains and suggested the two places that I had seen male moths in recent years: Old Buckenham village green and Chapel Green, Rocklands. This latter is a tiny plot of wildlife meadow that was restored by Rocklands Parish Council two decades ago through a Millenium Meadows grant, and financial support from Norfolk Rural Community Council, Norfolk County Council and guidance from Norfolk Wildlife Trust. It is a tiny (c. 0·015 ha) fragment of managed habitat that holds a surprisingly diverse and interesting flora and fauna, amongst which is a lek of Ghost Moths. I say lek, but when I checked back through my records I saw that I had only seen single males in June 2014, and (twice) in July 2016.

On D-Day, Thursday 6 June, despite a cool and windy evening, at 9.45 p.m.. I decided that I could no longer put off checking whether this year would produce an improvement on the singles that my memory had embellished into a weaving and bobbing troupe. I was fully prepared to tell James that the promised lek had not materialised and may have been unreliable in any case. What a relief to find two, then four, then finally a dozen male Ghost Moths "pendeculating" – Kettlewell's neologism for South's "swaying themselves to and fro without making progress".

The following evening, James was able to visit Chapel Green, arriving at 9.20 p.m. on his way back from another mothing assignment at Dungeness with moth expert Will Soar. For the first 20 minutes we enjoyed the meadow's wildflower display, twitching at passing Straw Dots Rivula sericealis and Common Swifts Korscheltellus lupulina (the latter a close relative of Ghost Moth) identified by Will. It was not until 9.40 p.m. that the first of our glowing white targets appeared, immediately followed by another, and another... Soon a group of six males were swaying and weaving on one side of the meadow, with another couple on the other. Our neighbour Carolyn, who coordinates the Chapel Green Management Committee, came out to enjoy the spectacle. We wondered if we might be lucky enough to see females, and shortly afterwards a dull yellowish brown female did indeed appear, immediately to mate with her chosen male. We found two pairs of mating moths, both on tall grass spikes, as well as a bloated female that was surely about to deposit her eggs. By 10.00 p.m. the display was over, and only these five Ghost Moths remained, clinging to their respective stems. The entire show had lasted exactly 20 minutes.

What is going on? A lek is an aggregation of male animals that come together, usually at a traditional site, to display together in order to compete for access to females. The phenomenon is especially well-documented in birds (particularly grouse and manakins) but not so widely-known in insects. In the case of Ghost Moths, the males hover over the grass, fanning their wings in order to release from scent brushes on the tarsus of the rear pair of legs a pheromone that attracts the females. The latter enter the lek briefly, select a mate, copulate on a grass stem and then fly off to drop their eggs over suitable grassy areas. The process was diligently observed and described by Mallet in his 1984 paper.

Formerly common, Ghost Moth is now a UK Biodiversity Action Plan species, listed because its populations are declining markedly. Conservation of this and a suite of other disappearing grassland plants and animals species is precisely the reason that Rocklands Parish Council manage this small area as a wildflower meadow.

More information?

Ghost Moth on NorfolkMoths here.

Rocklands Parish Council Chapel Green wildflower meadow page here.

Previous posts about management of Chapel Green wildflower meadow here.

James Lowen's blog here.


Kettlewell, H.B.D. (1973) The evolution of melanism. Clarendon Press: Oxford. 423 pp.

Mallet, J. (1984) Sex roles in the ghost moth Hepialus humuli (L.) and a review of mating in the Hepialidae (Lepidoptera). Zoological Journal of the Linnean Society 80(1): 67–82. PDF.

South, R. (1908) The moths of the British Isles, second series. Frederick Warne & Co.: London. 388 pp.


James Lowen's wonderfully illustrated account of tonight's display here.

On the evening of 11 June, despite cool temperatures (10°C), moderate drizzle and a damp SE 2–3 breeze, we counted at least 14 males lekking for exactly 20 minutes 2149–2209. The females are more difficult to spot, but we did see two come in and mate with males. The mild (15°C) evening of 17 June was even more active, with a high count for this year of at least 32 males and 4+ females between 2155 and 2215 (and perhaps later, as I left while it was still in full swing). A quick visit at 2210–2220 on the cool (14°C), evening of 22 June showed 24 males lekking, along with 1 female, though did not have time to check thoroughly.

Tuesday, 28 May 2019

Red Knot (Calidris canutus rufa) resighting in Venezuela and Canada

Red Knot FELG9HL, Falcón, Venezuela, 29 Mar 2019. Photo: Gianco Angelozzi
On 29 March, a team of ornithologists working on a Western Hemisphere Shorebird Reserve Network project (Sandra Giner, Virginia Sanz, Gianco Angelozzi and I) were carrying out International Shorebird Censuses on the Punta Maragüey spit on the western coast of Falcón with Jose Ochoa. Gianco was able to get close to a flock of several hundred Red Knot (Calidris canutus rufa) moulting into breeding plumage, and using our best optics - a superb new Kowa scope donated in 2018 by Cley Spy - to pick out and photograph seven flagged individuals, of which only FELG9HL was legible; this bird also carried a geolocator (Gianco's photograph attached - more here).

Red Knot FELG9HL, Ontario, Canada, 20 May 2019. Photo: photographer unknown
Today I checked the bird's whereabouts and found that it had been photographed (attached - photographer unknown) 52 days later on 20 May in magnificent full breeding plumage at a reservoir W of Townsend in S Ontario, Canada. This elucidates only part of the jigsaw puzzle of migratory connectivity for this threatened shorebird, and quite appropriate given that this Manomet / WHSRN work is financed by Environment Canada. Next stop for these birds will be the high Arctic. The earliest data available for FELG9HL come from 30 May 2011 in Delaware, so the bird is perhaps 10 years old and will have made this journey as many times.

Tuesday, 7 May 2019

Book review: Birds of Central America: a field guide

Birds of Central America: Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panama

Andrew C. Vallely & Dale Dyer
Princeton University Press | 2018
584 pp. | 16 x 23.5 cm | 260 colour plates, 1261 maps
Softback | £40 / $49.50 | ISBN: 9780691138022

Just finished my review of the superb new guide to the birds of Central America, to be published in Neotropical Birding 25...

Thanks to Princeton University Press for providing a review copy.

Published review below, PDF here.

Until recently, field guides for Central America were getting rather long in the tooth, although such masterworks as Howell & Webb (1995), Stiles & Skutch (1989), and Ridgely & Gwynne (1989) never become obsolete. The situation was remedied by the first field guides to Belize (Jones 2003) and Honduras (Gallardo 2014), followed by pocket guides to Costa Rica (Garrigues & Dean 2007), Panama (Angehr & Dean 2010) and Nicaragua (Chavarría-Duriaux et al. 2018; see review, page 88) published by Zona Tropical/ Comstock Publishing Associates (latterly imprints of Cornell University Press), and by the Peterson guide to Northern Central America (Fagan & Komar 2016). The present volume, as the first field guide to the entire Central American avifauna, fills the gaps left by El Salvador and Guatemala and brings the identification literature for the remaining countries up to date.
     A decade in production, the book covers the 1,261 bird species that had been documented in the political region of Central America as of August 2017, an avifauna comparable in size with that of a typical South American country – quite a daunting undertaking. Each of the 1,194 bird species of what the authors define as the ‘core avifauna’ is accorded a main species account, while a further 67 ‘marginal, dubious and hypothetical species’ are relegated to an annotated appendix.
     The region is delimited politically rather than biogeographically, so Vitelline Warbler Setophaga vitellina, a West Indian species found only on the Swan Islands and (extralimitally) on the Cayman Islands, is included. Taxonomy and order broadly follow American Ornithological Society (AOS). There are some logical departures, such as treating Audubon’s Setophaga auduboni and Goldman’s Warblers S. goldmani as separate from Yellow-rumped Warbler S. coronata, or recognising Azuero Parakeet Pyrrhura eisenmanni as distinct from South American Painted Parakeet P. picta.
     The main accounts comprise carefully distilled, concise identification texts and good-sized distribution maps (29 x 36 mm) on the left, with plates on facing spreads. Layout is intuitive, facilitating cross-referencing to the facing page. For species that exhibit geographic variation northern/western subspecies appear on the left-hand side of the plate and eastern/southern subspecies on the right. Plates are the most realistic of any guide to this region, accurately capturing the jizz and plumage of all groups. Birds are usually shown in profile to facilitate comparison, but the illustrations have a pleasing three-dimensional quality and the plates themselves are works of art. The antbirds and furnariids are spectacular. The figures are large and fill each plate, leaving minimal blank plate.
     Critical groups such as shorebirds, tyrant flycatchers and warblers are very nicely illustrated, the latter with both breeding and non-breeding plumages. There should be no need to carry an additional guide to the birds of North America. It is no surprise to learn that both artist and author spent a great deal of time in museum collections, especially the American Museum of Natural History, checking and comparing specimens. The depth of their research is apparent in the quality of the entire book. It may take a while for the eye to adapt to the lack of colour saturation of the plates, particularly for some groups like vireos and thrushes. However, I find the artwork very pleasing.
     In the introduction, the authors set out their reasons for not labelling figures with subspecies names; having examined the full range of geographic variation they felt that a more general description of geographic variation was more appropriate. Given the diligence with which the authors examined museum specimens, I would have liked to have seen scientific names of subspecies specified, which I think would have added clarity to accounts of, for example, Willet Tringa semipalmata, Short-billed Dowitcher Limnodromus griseus, Osprey Pandion haliaetus, Dusky-capped Flycatcher Myiarchus tuberculifer and Northern Rough-winged Swallow Stelgidopteryx serripiennis.
     Text focuses squarely on the task of identification. In the interest of brevity, it omits information on aspects of life history except where they aid identification. An introductory line on regional and global status precedes the main identification text, which is followed by a short section covering geographic variation where appropriate. Notes on habits indicate habitat preference, the favoured habitat stratum (canopy vs understorey, etc.), and distinctive features of behaviour. The final section describes vocalisations. The compilation of accurate distribution maps across seven nations must have consumed an inordinate amount of time. I could find no obvious oversights, although unfortunately Turquoise-browed Eumomota superciliosa and Blue-throated Motmot Aspatha gularis maps have been transposed during layout. The authors have wisely treated records on popular online platforms with caution, which will ensure that the distributional data provides a solid baseline for future work.
     Compressing practical information on the identification of 1,200 species into one volume demands a good-sized book. This one is about the size of old guides such as Stiles & Skutch or Ridgely & Gwynne, and weighs 1.3 kg. Yes, for those who want to carry a pocket guide, it is bulky, and also heavy. And it is likely that many visitors will be inclined to pass it over in favour of a lighter guide. In my opinion that would be a mistake. I much prefer to carry a dependable, authoritative reference and will gladly have this in a backpack in preference to a smaller guide. At the very least, for those who will not be taking it in the field, it should be an essential reference for consultation back at camp or at the hotel.
     So, an excellent addition to the literature on the birds of Central America with strong text and plates. This new guide becomes the benchmark for the region and acts as a worthy geographical complement to Howell & Webb (1995), with a slight geographic overlap. The authors deserve the highest praise for a magnificent achievement.
Christopher J. Sharpe 

Angehr, G. R. & Dean, R. (2010) The birds of Panama. Ithaca, NY: Comstock Publishing Associates.
Chavarría-Duriaux, L., Hille, D. C. & Dean, R. (2018) The birds of Nicaragua: a field guide. Ithaca, NY: Comstock Publishing Associates.
Fagan, J. & Komar, O. (2016) Peterson field guide to birds of northern Central America. New York: Houghton Mifflin Harcourt.
Gallardo, R. J. (2014) Guide to the birds of Honduras. Honduras: Mountain Gem Tours.
Garrigues, R. & Dean, R. (2007) The birds of Costa Rica: a field guide. Miami, FL: Zona Tropical.
Howell, S. N. G. & Webb, S. (1995) A guide to the birds of Mexico and northern Central America. Oxford, UK: Oxford University Press.
Jones, H. L. (2003) Birds of Belize. Austin, TX: University of Texas Press.
Ridgely, R. S. R. & Gwynne, J. A. (1989) A guide to the birds of Panama, with Costa Rica, Nicaragua and Honduras. 2nd edition. Princeton, NJ: Princeton University Press.
Stiles, F. G. & Skutch, A. F. (1989) A guide to the birds of Costa Rica. Ithaca, NY: Cornell University Press.