Birds of Mongolia

After a long wait, with the publication of Birds of Mongolia Mongolia finally has a comprehensive field guide, something that will be invaluable to birders visiting this exciting country. Although Mongolia has only one recognized endemic, Kozlov’s Accentor, it has breeding populations of a diversity of highly sought-after species which, combined with wonderful scenery, unbeatable clear skies, clean air, and the silence of many of its remote birding spots, is enticing more and more birders to visit this vast country. Much of Mongolia remains a wilderness, supporting very important populations of species that are everywhere under increasing threat.

Situated on a mountainous high plateau, with an average altitude of around 1,500m, Mongolia stretches some 2,400km from east to west and 1,250m from the Taiga Forest in the north, through extensive Steppes, to the Gobi Desert in the south. Despite its enormous size, this country supports a human population of little more than 3 million people. Consequently, many areas remain remote and difficult to access, and any serious birding trip to the region must take the form of a well-organized expedition. Nevertheless, during a 2-3 week trip to Mongolia in late spring or early summer one can expect to see an assortment of birds on their breeding grounds including such enigmatic species as Black-billed Capercaillie, Altai Snowcock, Swan Goose, White-naped Crane, Relict Gull, Oriental Plover, Asiatic Dowitcher, Brown-cheeked Rail, Henderson’s Ground Jay, Pallas’s Sandgrouse, White-throated (Hodgson’s) Bush Chat, Eversmann’s Redstart, Mongolian Lark, Blyth’s Pipit, Azure and Siberian Tit (Grey-headed Chickadee), Siberian Jay, Wallcreeper, White-crowned Penduline Tit, Chinese Bush Warbler, Altai and Pere David’s Snowfinch, and Pallas’s Reed and Yellow-breasted Bunting. Numerous migrants also pass through Mongolia, and even as late as the end of May one can still find small numbers of species on migration such as Little Gull, Hawfinch, Naumann’s Thrush, Pallas’s Grasshopper Warbler, Little Bunting, and Arctic Warbler. Visits by birders in the winter months are rare because of the extreme cold conditions.

This field guide is classic in its format, with plates arranged opposite the text and maps. The introductory section provides a brief introduction to Mongolia and describes its main ecological zones and habitats. This interesting section is illustrated with maps and a nice selection of photographs depicting distinctive habitats. There are also short sections on migration, conservation, and protected areas. The section on conservation, however, seems to be based on an old version of the BirdLife Red Data Book. Now, Yellow-breasted Bunting is considered to be Critically Endangered, whilst Pallas’s Fish-eagle is Endangered and the list of Vulnerable species that occurs in Mongolia has also changed. Moreover, the Critically Endangered Sociable Plover has been omitted from the list of threatened birds in the Introduction.

The Introduction also includes a section about Birdwatching in Mongolia which highlights a sample of Important Birding Area. This section can be a little misleading, however, because it sometimes fails to differentiate which species occur at which sites at particular times of year. For this, one has to refer to the maps. The final part of the introduction is a standard section on how to use the book.

The main part of the book, 226 pages, is devoted to the species accounts, which covers 503 species. Each species is illustrated opposite the text that describes it, along with the distribution map. The text includes short sections on Identification, Voice, Habitat, Behaviour, Status, and Taxonomy where relevant. Overall most of the text is succinct and useful, but the voice descriptions, as with the majority of field guides, are often not particularly helpful. This book was originally commissioned as part of the Helm Field Guide series, and as a consequence many of the illustrations are identical to those used in other guides in the series, including the guides for East Asia and Central Asia. Altogether, 12 artists were involved in depicting the species in the book, but despite some differences in style, on the whole the plates are very good.

The taxonomy (with some, unspecified “exceptions”) follows that of IOC version 8.2. (2018). This, of course, has now been superseded, and species in version 9.1 that are not recognized by this field guide include Eastern Yellow Wagtail Motacilla tschutschensis and Stejneger’s Stonechat Saxicola stejnegeri. The text is brief, which suffices for the great majority of species, but is insufficient to differentiate some of the trickier birds likely to be encountered. For example, you could not use this book alone to safely identify some of the warblers, to separate the two taxa of Siberian Stonechats (one being Stejneger’s, mentioned above), or even some of the better-studied species such as Blyth’s and Richard’s Pipits unless singing. In this respect, it is a pity that the authors did not follow the example of the recent Birds of Central Asia (Ayé et al. 2012), which follows the same format, has many of the exact same images, but a significantly more detailed text in respect to identification where deemed necessary.

Like the font for the species accounts, the maps are relatively small. Each base map shows some topography, using three shades of grey to indicate particular altitudes. These grey shades are overlaid with other colours indicating resident, breeding visitor, winter visitor, and migrant status. The maps become a little complicated as a consequence, although it is often very useful to be able to see whether a species occurs in the mountains or plains. Most of the maps are probably as accurate as can be expected for a country that is relatively poorly-known.

One species for which the map is almost certainly wrong is Mongolian Short-toed Lark Calandrella dukhunensis. IOC treats this recently-recognized species as monotypic, but this guide refers to subspecies longipennis as breeding in the west of Mongolia. This latter taxon, however, is usually considered to be a subspecies of Greater Short-toed Lark C. brachydactyla (by IOC and other authorities), and hence Greater Short-toed Lark should be included in the Mongolian bird list (it occurs in western Mongolia). Vocal and other evidence suggest that Mongolian Short-toed Lark may only breed in the easternmost quarter of the country, and does not occupy the vast range that is depicted in the book.

It is also a shame that maps do not delineate the ranges of a few of the more distinctive subspecies, such as the two races of Horned Lark Eremophila alpestris brandti (“Steppe Horned Lark”) and E. a. flava (“Shorelark”) since there is a possibility that they will be split in the future. Indeed, “Khangai Rosy Finch” Leucosticte arctoa sushkini is so different from nominate Asian Rosy Finch that is seems destined to become a Mongolian endemic. The two subspecies of Pallas’s Reed Bunting Emberiza pallasi occurring in Mongolia are also of taxonomic interest, with some evidence that the southern subspecies lydiae might be a different species (“Mongolian Bunting”). Despite the fact that there are some seemingly reliable records from Mongolia of Red-tailed Shrike Lanius phoenicuroides, it is not mentioned in Birds of Mongolia. This taxon has been treated as a full species by IOC and most other contemporary authors for some time, but was previously a subspecies of Isabelline Shrike L. isabellinus. So, at the very least, it should really have been mentioned and illustrated in this book under the latter.

An even more glaring example of a species that deserves more space and comment is that of Lesser Whitethroat Sylvia curruca. The account for Lesser Whitethroat, presently treated as a widespread polymorphic species, illustrates only a single breeding and a single 1st winter bird, whilst the text does not mention anything about the subspecies that occur in Mongolia, or how they might differ in plumage or use of habitat. Whilst range maps in Shirihai et al. (2001) suggested that only halimodendri and curruca occur in Mongolia, subsequent mitochondrial DNA studies by Olson et al. (2013) revealed that both margelanica and blythi also occur in Mongolia. The latter study also revealed that blythi is more closely related to Hume’s Whitethroat S. althaea than it is to any of the other taxa presently treated as Lesser Whitethroat. Hence these taxa very likely represent several cryptic species, of which as many as 3-4 might occur in Mongolia. Whether the authors overlooked this or ignored it because of the complexity involved is unknown, but it is a lost opportunity that this guide does not even mention the Lesser Whitethroat taxa likely to be encountered in the country. For serious birders visiting Mongolia, it is worth paying particular attention to any Lesser Whitethroats encountered.

Another species that deserves comment is Beijing Babbler Rhopophilus pekinensis. The inclusion of this species is based on two “vagrants” at an oasis in the Trans-Altai Gobi. This raises a question, because based on range and habitat, these seem much more likely to have been Tarim Babbler R. albosuperciliaris. Unless there are specimens available (no records from Mongolia are mentioned by Leader et al. 2013), it would probably be better to treat this record as Tarim Babbler or perhaps Rhopophilus sp. Indeed, a map in Leader et al. (2013) indicates that a specimen of Tarim Babbler was collected in China very close to the border with Mongolia, not far from where the 1943 record mentioned in this book is mapped. Furthermore, it seems very unlikely that this species would be a vagrant, since both species of Rhopophilus are thought to be resident species. The occurrence of two individuals together also calls into doubt the status of “vagrant”, and it seems quite likely that a serious search for this species in the right area and habitat might well uncover a breeding population. The bird illustrated in Birds of Mongolia is certainly a Beijing Babbler: Tarim Babbler has a dark eye, is less streaked above and has much less colour on the underparts.

At the end of the book is a section entitled Recent Vagrants and Hypothetical Records, although the statement that “these records have all been thoroughly reviewed and accepted by the Mongolian Bird Taxonomy and Rarity committee” seems at odds with including “hypothetical” in the title. It is a shame that these 20 species did not get included in the main text, especially considering that almost all of the records cited are from before mid-2016. It is also strange that, for example, Mountain Hawk-Eagle Nisaetus nipalensis is included in the main text based on a single record that “lacks documentation”. Surely, if any species should be considered hypothetical, this would be one of them. From reading the text, Red-footed Falcon should also perhaps be considered hypothetical (based on one undated record and other “doubtful records”), along with Grey-faced Buzzard (included on the basis of “a single unconfirmed sight record”).

Clearly, there is a lot more to be learned about Mongolia’s avifauna, and careful documentation of unusual records is worth bearing in mind for anyone birding in this fabulous country. Even species that many might find mundane, such as Lesser Whitethroat and smaller species of lark, deserve careful observation. Since this book went to press, at least two new species have been found in Mongolia by diligent birders – Water Rail Rallus aquaticus and Velvet Scoter Melanitta fusca.

Despite the relatively minor inconsistencies and other minor issues mentioned above, Birds of Mongolia is a very welcome book and the only comprehensive field guide to the birds to Mongolia. It is fit for purpose and undoubtedly the guide that any birder visiting Mongolia should turn to first. I look forward to using it on my next visit!

– Reviewed by Frank Lambert

References:

Ayé, R., Schweizer, M. and Roth, T. 2012. Birds of Central Asia. Christopher Helm, Bloomsbury, London

Leader, P. J., Carey, G.J and Holt, P.I. 2013. Species limits within Rhopophilus pekinensis. Forktail 29: 31–36.

Olsson, U., Leader, P.J., Carey, G.J., Khan, A.A., Svensson L. and Alström, P. 2013. New insights into the intricate taxonomy and phylogeny of the Sylvia curruca complex. Molecular Phylogenetics and Evolution 67: 72–85.

Shirihai, H., Gargallo, G., Helbig, A., Harris, A., Cottridge, D., Roselaar, D., 2001. Sylvia Warblers: Identification, Taxonomy and Phylogeny of the Genus Sylvia. Christopher Helm, A & C Black, London.