Tuesday, 14 March 2017

European Amphibians and Reptiles: A New Field Guide

Field Guide to the Amphibians and Reptiles of Britain and Europe by Jeroen Speybroek, Wouter Beukema, Bobby Bok and Jan Van Der Voort and illustrated by Ilian Velikov. London: Bloomsbury.

There is no greater delight for those of us who live in a country with few species of reptiles and amphibians than seeing active lizards, amphibians and chelonians in southern Europe. With the thought of a Naturetrek trip to Albania in a little under three weeks, I wondered if there was anything more suitable to take with us than the 2002—and latest—edition of Collins Field Guide to the Reptiles and Amphibians of Britain and Europe that was written by Nick Arnold. As a field guide I find that book extremely irritating in that descriptions, illustrations and distribution maps of a species are in different sections of the book. I also thought I should be au fait with the inevitable taxonomic inflation that must have occurred. Hence, I found the almost identically titled but differently authored book from a different publisher that appeared last year.

I do not envy anybody the task of producing a field guide or even a check list. What does one do when a paper is published that splits a species on the basis of the phylogenetic species concept or genetic species concept rather than the biological species concept? And how does one then present that evidence in relation to the morphological semi-splitters of the past who created a new subspecies for virtually every locality specimens were collected from? 

Molecular systematists have had a whale of a time generating data on European reptiles and amphibians but you can take it from the preceding paragraph that I am by no means convinced that many of the species being described on the basis of differences in a few genes are ‘good species’ that hold up to the scrutiny of the biological species concept. Returning to the writing of field guides, authors tend to fall into the trap of having to appear modern by including every ‘split’ and, therefore, every change in taxonomy proposed. I will return to this question later.

The new book is clearly written as the herpetological equivalent of the area or country guide for birdwatchers (who come in many different guises and with different interests). The authors, before moving on to the description of individual species, devote chapters to: the diversity and origin of the European species, including the retreat to the separate refuges in the south during the Ice Ages and then re-colonisation as the ice melted; advice on how to, and where to, watch the European species; the identification of amphibian eggs and larvae. The diversity chapter includes a section on threats, such as the spreading of disease by herpetologists themselves, and conservation efforts. There is also complete checklist of species.

How does it compare with Arnold’s book of fourteen years earlier? For that comparison, I will divide this review into four parts.

Firstly, as a field guide, Speybroek et al. is much better. Descriptions, maps, illustrations and photographs are close together. However, it is not perfect because each species (or closely related groups of species) does not start at the top of a page. The publishers seem to have been trying to ensure that the book fitted into a set number of pages, in this case 432. However, in doing so, they have been wasteful of space. The illustrations are too big for the amount of information they convey. The whole design could have been much ‘tighter’ and the book, therefore, lighter in the pocket or backpack. The book weighs 740 g covering 219 species. The Collins Bird Guide for Europe covers over 700 species but weighs just 700 g.

The illustrations are more extensive and, ignoring the excessive white space, are good but no better than those of Denys Ovenden who illustrated Arnold’s book. There are some oddities. For example, the main illustration of the Ibiza Wall Lizard is captioned ‘brightly coloured individual’ and looks nothing like any of the lizards I have seen on Ibiza (although there are photographs of this form on a few websites). The photograph on the next page, from an introduced population on Mallorca, is however typical of those usually seen. Perhaps some of the species needed several illustrations to display the range of local variation in coloration.

Secondly, as a guide to the taxonomic changes or the authority on which changes have been made, this book falls short. The description of what happened during and after the Ice Ages is not linked to possible speciation and taxonomy The explanation under the heading ‘New species, new names’ is superficial. I have touched on the difficulties in drawing up a definitive list of species. It seems to me that the authors—and they are not alone—have adopted as species whatever those proponents of species concepts other than the biological species concept have proposed as species. But they do not say so or comment in any way on which species concept(s) they consider valid. The authors conclude the section: ‘Luckily, the majority of European amphibian or reptile species has nowadays been studied from a genetic viewpoint, making future name changes increasingly less likely, but never entirely out of the question’. Wanna bet?

Thirdly, In terms of biology, there are some serious omissions. It is mentioned that the two Bombina species hybridise but there is no mention of the narrow hybrid zones that have been studied extensively and which have contributed so much to knowledge of speciation and introgression. There is also no mention of the special place of the Edible Frog in biology; there is not even an explanation of the ‘kl.’ in its modern scientific name. Given its and other European forms’ key status as examples of hybridogenesis, in this case between the Pool Frog and the Marsh Frog, it does seem odd that the phenomenon is not even given a mention. Compounding this omission is the appearance of the distribution of the Pool and the Edible frogs together on one map and of the Marsh Frog on another. And yet the authors found lots of space for the itemisation and description of subspecies rather than simply the extent and nature of geographical variation. And, yes, you can take it that I regard the whole concept of subspecies and formal trinomials as deeply flawed.

Fourthly, in terms of geographical coverage, Arnold includes the Canary Islands and Madeira; Speybroeck et al. does not. I cannot understand why Britain was included in the title or included in the publisher’s British Wild Life Field Guides series. Yes, the maps include the distribution in Britain, but anybody seeking information on British reptiles and amphibians would be better looking elsewhere. 

In conclusion, while I found myself disappointed by the lack of coverage of some topics, as a field guide, the new book wins simply on the grounds of better arrangement of descriptive text, illustrations and maps. It is the one I will pack.

Writing such a book as this cannot have been an easy task, with decisions on what to leave out being a lot harder than what to keep in, but throughout the enthusiasm of the authors and illustrator shines through. For example, Jan van der Voort, a civil servant whose photographs appear throughout the book, has photographed every species in Europe. Who can resist the end of the Preface by Jeroen Speybroeck:

There is nothing quite like the the enchantment offered by a sizeable frog chorus in a Bulgarian swamp comprising a mixture of tree frogs, fire-bellied toads, green toads, spadefoot toads and water frogs. Reptilian thrills are plentiful, such as finding your first chameleon, bumping into mating tortoises, or experiencing the thrill of chasing down a feisty whip snake. I hope this book will foster the fascination in many more people, albeit always with respect for the animals and the conservation of them and their natural environment.

Amen to that.