Friday, 31 March 2017

The butterfly’s tongue and the steel rule

‘Why is that there?’, said my four-year old grandson in an accusatory tone when he spotted a Stanley coiled flexible steel rule on my desk. ‘Ah, I need to take a photograph of it to show how a butterfly’s tongue works’, I replied. A look of utter puzzlement and then of disdain on the boy’s face demonstrated his certain knowledge of having a silly grandfather.

L.E.S. Eastham
My wish to illustrate this post with a steel rule was occasioned by a jolt of memory when I was writing a previous one on BEPS—The Invertebrata by Borradaile, Eastham, Potts and Saunders. I had a vivid recollection of the words being said, but not of the face behind the words, during a lecture at Sheffield on insects that in the old days (i.e. before 1958 when Eastham retired as Professor of Zoology) we would have had to have known how the butterfly proboscis works since he, Eastham, it was who worked it out. However, the lecturer added that the only thing about the mechanism that one had to remember was that it works like a steel rule. The more I thought about who the lecturer was, I have the vague notion that it was the Sheffield born-and-bred—and educated—Fred Segrove (1911-2003).

Having remembered nothing else about the butterfly proboscis, I recently found the original paper by Eastham and Eassa, published in 1955 when Eastham was 62. It is a highly impressive and long paper and involved making serial sections and some physiological studies. It demolished previous theories on how the proboscis worked. Eastham himself provided a short explanation in the later editions of BEPS:

The adults live on the nectar of flowers, and to absorb this a highly specialized proboscis has been formed from the greatly elongated galeae of the maxillae, each being grooved along its inner face and locked to its neighbour…Each half of the proboscis is a tube in itself into which passes blood from the head, and also a trachea and a nerve. Across the cavity of this tube there pass a number of oblique muscles. At rest the proboscis is tightly coiled like a clock spring under the head. When feeding the proboscis is extended and its tip placed in the food source. It is now recognized that the elastic properties of the cuticular wall of the proboscis account for the coiled condition when resting. Extension of the proboscis is brought about by the internal oblique muscle of each galea. These, working in conjunction with a stipital valve controlling the closure of the passage between cephalic and galea haemocoeles, cause the proboscis to develop a dorsal keel along its whole length. The attainment and retention of this new shape depends on the turgidity of the galea tube and the elasticity and flexibility of parts of the cuticular wall. For mechanical reasons it cannot in the keeled position be retained in the coiled state and extension of the proboscis results.In feeding, a complex pharyngeal muscular apparatus causes the fluid food to be sucked into the mouth. The length of the proboscis in many cases corresponds to the depth of the corolla of the flower which the species frequents, and in the Sphingidae (hawk moths) may be greater than that of the body…

In Eastham’s chapter in BEPS there is though no mention of the analogy of a retractable, flexible steel rule, which was used in the original paper and in which a Mr F.W. Adams was thanked for thinking of it:

…a coiled steel rule, when coiled in its case, is flat in section, but when it is drawn out it assumes a curved transverse section, convex on one side and concave on the other, and in this state attains a condition of extension. In this case the rule has to be forced into its case, and bending can only occur when its transverse curvature is flattened out. The condition of rest is one of extension and force has to be applied to coil it up, the rule having been manufactured with these properties.

The difference between a steel rule and a butterfly’s proboscis is, of course, that it is muscular action which produces the curved transverse section for extension and elasticity which returns it to a flat cross section after the muscles relax and thence its recoil.

Small Tortoiseshell with proboscis coiled

Comma feeding with proboscis extended. Eastham & Eassa also explained
how the 'knee-bend' in the proboscis was formed

There is an statement in the paper which sixty-odd years after it was written I find odd:

…As a result of complete analysis of these structures, of observations on the animal during feeding—of numerous operations involving nerve sections and perforations of the haemocoele—a new theory is offered on the proboscis mechanism for which the senior author (L.E.S.E[astham]) alone is responsible.

I can think of several explanations for this statement. Did Eassa disagree is one. Did Eastham think that if the new theory were to be shot down in flames, he was making sure that Eassa could not be blamed? But then the paper was sent to the Royal Society for publication by V.B. Wigglesworth, the name in insect physiology in the 20th Century; he must have been sufficiently impressed. There remains the possibly unworthy thought that Eastham was making sure he got the credit but that goes against Eastham’s reputation in Sheffield amongst those who had worked in his department like E.T.B. Francis, F. Segrove and J.D. Jones as a gentlemanly, paternal figure. And what had Eastham to gain at the age of 62 and three years from retirement? The only possibility is that he was, and perhaps for the last possible time, up for election to the Royal Society. He, like all the other authors of BEPS, was not elected but I do not know—and cannot know until the archives for that period are opened—if he was ever proposed.

But what of Eassa? Who was he, what was he doing in Sheffield and what happened to him?

Youseff Ezeddin Eassa (1914-99) was a famous Egyptian author as well as being Professor of Zoology at the University of Alexandria. There is a website devoted to him and his work. He was a graduate of the University of Cairo and is shown as arriving in Sheffield in 1948 as a Ph.D. student but also as an established playwright and author. However, his Ph.D. thesis (A contribution to the postembryonic development of the head of Pieris brassicae (Linn)) is dated 1949 so he may have travelled to Sheffield earlier than 1948. He must have stayed in Sheffield for some time after 1949 because the Eastham & Eassa paper was sent to the Royal Society in April 1954 and no new address for Eassa is shown.

While in Sheffield he wrote stories and plays that were broadcast on BBC radio. He recalled that his favourite companion at coffee was Hans Krebs, later Sir Hans and then Professor Biochemistry at Sheffield. Eassa was a Fulbright Fellow in Berkeley and Illinois in 1960-61.

Youseff Ezeddin Eassa (from here)

I hope I get the opportunity of explaining to my grandchildren not only how the butterfly feeds, using, of course, the steel rule as an aid, but also of making sure they know that international scientific collaboration was not invented by the EU (as some young academics in Britain clearly believe) and that academics could meet and exchange ideas in university staff (faculty for readers more familiar with the U.S. university system) clubs rather than remain ensiled, as appears to be the case at present, in departmental comfort zones.

Oh, and here is the rule:

Eastham LES, Eassa YEE. 1955. The feeding mechanism of the butterfly Pieris brassicae L. Philosophical Transactions of the Royal Society B 239, 1-43.

Thursday, 30 March 2017

The University of Hong Kong was a site for more than birds in the 1960s

In the 1960s, the University Compound’s pathways teemed at night with the toad, Duttaphrynus melanostictus (formerly Bufo melanostictus), along with introduced Giant African Snail, Achatina fulica.

Duttaphyrnus melanostictus

The lily pond had large numbers of Guenther’s Frogs (Sylvirana, previously Hylarana guentheri).

Lily pond, University of Hong Kong, constructed in the early 1950s. The trees

were non-native. From Mellor, B. The University of Hong Kong, An Informal
History.  Hong Kong University Press, 1980

After heavy rain, the gardeners disturbed a couple of the microhylid, Kaloula pulchra, outside our lab building, the old Building 15 of the medical school (which by 1965 had moved to its new quarters on Sassoon Road).

Kaloula pulchra

The same location revealed a couple of Brahminy Blind Snakes under an old flowerpot. This species, now going under the name of Indotyphlops braminus, has been introduced into many parts of the world in...flowerpots.

This photograph from 1950 shows a University Congregation processing along
Pokfulam Road. I found Kaloula pulchra over the wall to the right, 17 years later
All the building in view have been demolished. From Mellor 1980

Street lamps and flats had the Oriental Leaf-toed Gecko, Hemidactylus bowringii. They often looked thin and underfed like the one I photographed.

Hemidactylus bowringii

A squad of gardeners looked after the compound and cleared fallen leaves. Snakes were, therefore, not to be expected. However, we did one spot a couple of times an Indo-Chinese Rat Snake, Ptyas korros, on the ground at the base of a tree directly below our balcony at 3 University Drive.

The only other snake seen took me by surprise. I opened a lab drawer containing glassware one morning to find a White-spotted Slug Snake (Pareas margaritophorus) less than happy at being disturbed.

If only digital camera traps had been invented in the 60s, we might have got an idea what, if any, mammals, other than rats, mice and domestic cats and watchmen were living in or visiting the Compound. A Chinese Ferret Badger (Melogale moschata) or two would be my bet.

Oliver LA, Prendini E, Kraus F, Raxworthy CJ. 2015. Systematics and biogeography of the Hylarana frog (Anura: Ranidae) radiation across tropical Australasia, Southeast Asia, and Africa. Molecular Phylogenetics and Evolution 90, 176-192. 

Hedges SB, Marion AB, Lipp KM, Marin J, Vidal N.  2014. A taxonomic framework for typhlopid snakes from the Caribbean and other regions (Reptilia, Squamata). Caribbean Herpetology 49, 1–61.

Tuesday, 28 March 2017

Why was the University of Hong Kong a good site for birdwatchers in the 1960s?

In the early bird reports for Hong Kong, the University Compound (now called ‘campus’) often got a mention. There are two reasons. The first is that from Herklots in the 1930s there was often a birdwatcher or two living and working there. The second is that it was wooded hillside interspersed with green spaces, shrubberies, ponds and gardens. Some of the trees, unlike the wooden floors, window frames and roof timbers of the buildings, may have survived the Japanese occupation. The steep paths and steps (84 between the old Building 15 and 3 University Drive) allowed views into the tree tops.

1965 view from 3 University Drive over part of the University Compound.
The white buildings are on the north side of Pokfulam Road.
The partially hidden brick buildings were pre-clinical labs
vacated when the medical school moved to Sassoon Road

The compound was though already falling from grace in the early 1960s because of the spate of new building from the early 1950s (new staff flats) until the, for then, large new chemistry block, library, students’ union and first phase of Robert Black College. However, from 1965 until we left in 1968, the compound was undisturbed by new building.

The Compound. bounded by a nullah to the west. was a good place to see all the common Hong Kong birds including winter and summer visitors. It was also good for passage migrants (the delights of Po Toi island were then unknown). Blue and White Flycatchers appeared in numbers in April 1966. What are again named Ince’s or Chinese Paradise Flycatchers again (after a period of being lumped into Asian) appeared in the spring. We saw a spectacular fully-tailed male each day from 12 March until 5 April 1966.

Above the university and to the west of University Drive (now, I see renamed University Avenue), Conduit Path was good in the winter for thrushes and Rubythroats and the Violet Whistling Thrush was rarely absent from the sides of the nullah that, further downhill, bordered the Compound.

We overlooked the tree tops in the western part of the compound when we lived for a year in a flat in the very well designed 3 University Drive (now demolished). Cicadas in the evenings and bulbuls  by day were the overwhelming sounds. All could be heard because traffic on Pokfulam Road was relatively light. Large insects flew on to the balcony in the evenings, once pursued by a Collared Scops Owl that did a quick about turn when it saw me.

However, the green and pleasant old Compound did not last. High-rise building followed high-rise building as student numbers increased. Departments housed on the north side of Pokfulam Road were moved into the Compound as the buildings were demolished for road widening. The old preclinical medical buildings were cleared and huge blocks replaced the gardens.

Writing in 1983 in what was then the University’s newspaper, Interflow (Issue 39, March 1983), the late Harry Edie, a botanist, questioned what was going on under the self-explanatory title, 'Tropical Paradise or Concrete Inferno'. In making a plea for expert botanical input into planning the campus in order to preserve wildlife and continue to provide amenity value to the human inhabitants surrounded by closely packed tall buildings, Harry showed photographs of the Compound as it was in the 1970s.

One of Harry Edie's photographs showing the University Compound in
the 1960s and early 1970s
Another Harry Edie photograph showing the (non-university) hillside
in the foreground. No 3 University Drive is front central; No 2 is the
orange block. Robert Black College has the blue roof. The Vice-
Chancellor's Lodge is on the far left. The large block of flats is beyond
the University Compound.
Photograph of 3 University Drive from Harry Edie's article. Note the
lush vegetation of the gardens
1966 view from Conduit Path. The University Library is left; 3 University
Drive is front centre and the old house on University Path is right.
All now demolished except the library

The general sub-tropical regrowth of trees and plants incorporated into landscape designs did mean that in the 1990s the Compound was still a good habitat for birds, even though much of the land area was covered by concrete. Between the 1960s and 1990s a number of species expanded their ranges. For example, apart from isolated reports the only reliable site for Fork-tailed Sunbirds in the mid-1960s was Tai Po Kau Forest Reserve in the New Territories. By 1997, a pair was nesting in creeper at Robert Black College a short distance from our room.

Further expansion of the University, this time with blocks built to the west of the old Compound has completely altered the landscape in the past fifteen years. But some of the old trees and wilder areas remain and new planting around the buildings can be seen. It is difficult to assess by occasional visits at different times of year whether the Compound, sorry Campus, still provides a stop-over for passage migrants or suitable habitat for the common residents and seasonal visitors.

The Hong Kong Birdwatching Society no longer lists the University as a good site but it does include the land above it—Lung Fu Shan.

Tuesday, 21 March 2017

A revision of an iconic textbook on invertebrates—the famous ‘BEPS’—was panned by a reviewer in 1958

It is hard to imagine that one of the advanced textbooks which you only got your hands on in the VIth form and which lived with you until the end of an undergraduate course in zoology took a pasting from a reviewer for New Scientist

The mention of ‘BEPS’, as the book was known throughout the world often brought forth the chant of its authors as a sort of mediaeval religious incantation: Borradaile...Eastham.....Potts.......and Saunders*.

This is what the review (New Scientist 17 July 1958) of the third edition said:

The Invertebrata. A manual for the use of students. By L. A. Borradaile, F.A. Potts, L. E. S. Eastham and J. T. Saunders. 3rd Edition revised by G. A. Kerkut. (Cambridge University 
Press, 795 pp., 55s.) 
BEPS has been the standard English text-book on invertebrate animals for twenty-five years, and will be familiar to anyone who has taken even the briefest University course in zoology. It is a fact book for undergraduates, for more senior zoologists in search of their memories, and for sixth-form libraries This new edition will maintain, but not enhance, its reputation as a useful but dull book. Of the four original Cambridge authors, only one. Professor Eastham, has been in a position to revise his part, and the whole has been undertaken by Dr. G. A. Kerkut, of Southampton. 
     The changes in the text are not large, and much of the increase of seventy pages is due to the addition of a useful appendix on zoological literature and to an increase in the number of illustrations. The text has been broken up into a series of paragraphs with sub-headings. which gives a somewhat staccato effect to the whole. Many errors of fact have come through unaltered, as have many general passages which were badly in need of reshaping in the light of new information. Some of the alterations have been made necessary by changes or expansions in the classifications used. Some of these are for the better, some for the worse; but the reader is now given a minimum of 400 group names to be learnt, in place of 280. 
     The earlier editions left out a few small groups. Some of these have now been included, but others are still ignored. For example, Kinorhyncha and Priapulida now appear, but Mesozoa and Symphyla, both of which are of more interest, are absent. 
     Most of the old and excellent illustrations reappear, and these have been improved by transferring the names of structures illustrated from the captions to the guide lines. But they are supplemented by new drawings, and some of the old ones have been redrawn. Manyof these arc technically execrable and some banal in content as well. A comparison of Figure 218 in the second edition with Figure 226 in the new will illustrate both these faults. 
     Revision of a standard text-book is an onerous task which no one would undertake lightly, and, where the textbook is one that will be largely used by students, its publishers must carry considerable responsibility. This one falls short of what is to be expected of so distinguished a house. 
R. B. Freeman.

[Richard Broke Freeman (1915-1986) was Reader in Taxonomy at University College London although he is probably best remembered as a bibliographer and expert on Charles Darwin.]

The first edition of BEPS was published in 1932 By 1958 two of the original authors (Lancelot Alexander Borradaile 1872-1945; Frank Armitage Potts 1882-1937) were dead. John Tennant Saunders 1888-1965 (grandfather of Jennifer Saunders the comedian and actress) had recently retired as Principal of University College, Ibadan, Nigeria. Leonard Ernest Sydney Eastham (1893-1977) was about to retire from the chair of zoology at Sheffield but revised his section on insects. Gerald Allan Kerkut (1927-2004) was responsible for the revision of the third and fourth editions; it was not his last book to be panned by a reviewer.

Was the poor reception of the third edition of BEPS in 1958 the reason why a fourth appeared in 1961?

What I think this rather sad tale for the original BEPS quartet means is that textbooks do not age well. The whole style and treatment makes revision beyond a certain point difficult especially in such a wide-ranging book by a single author. BEPS was essentially a 1920s book hanging on into the 1960s. As fashions changed and as soon as an alternative appeared, in the form of Invertebrate Zoology by R.D. Barnes (Saunders, 1963), it was dropped. However, BEPS is still a good starting point for looking things up—if only I could find my copy.

L.A. Borradaile
F.A. Potts (from here)
L.E.S. Eastham (from here)

...and I cannot find a photograph of J.T. Saunders.

*The order of the authors is BEPS on the jacket and BPES on the title page, Eastham and Saunders being described as having ‘chapters by’.

Friday, 17 March 2017

Teddy Bears and Hamsters: A 1900s Pet Scam

Still on the European Hamster (Cricetus cricetus), I came across this story in The Zoo Story by L.R. Brightwell, a history of London Zoo published in 1952.

Leonard Robert Brightwell (1889-1962) was a well-known and prolific author and illustrator. He had strong zoological connexions since he illustrated The Science of Life for the authors, H.G. Wells, Julian Huxley and G.P. Wells.

In his chapter covering the decade 1901-1910 and under the heading of one of his drawings showing how Fellows of the Zoological Society were dressed at the time while looking at a far more intelligent Chimpanzee, he wrote on the appearance of a new toy:
     …A matter of unscientific interest also was the arrival from U.S.A. of that still popular nursery potentate, the Teddy Bear…It is now generally agreed that the toy was really inspired by the Koala, or Billy Blue Gum, an Australian marsupial. But we are all full of Teddy Roosevelt, his famous range of dentures, fire-eating speeches and highly coloured hunting adventures. Whatever the nursery favourite's real origin, it is from the irrepressible "he-man" president that it took its name. The toy's immediate and tumultuous popularity led to a strange development in the animal trade. Certain livestock dealers—with a shrewd eye for what the public evidently wanted—gave it the "Teddy Bear Rat". This was the hamster, a chubby, handsomely marked beast not unlike a guinea pig and so abundant in some parts of the Continent as to be a plague. This is the rodent said to have eaten the cruel bishop in the Rhenish “Mouse Tower". To launch such a dirt-cheap creature on the public at an extravagant figure seemed to the business mind elementary common sense. But the hamster unfortunately combines with the guinea pig's chisel teeth a very unguinea-pig-like temperament. It led to so many complaints and damaged fingers that the police eventually prohibited its sale. The Zoo soon had to refuse offers of Teddy bear rats, so eager were disgruntled householders to part with their spiteful pets.

The European Hamster has always had a terrible reputation for biting its keepers in captivity and for defending itself in the wild. George Jennison in his Natural History Animals of 1927 wrote:
     It is an irascible creature, a bold and determined fighter with its own kind and against vultures and smaller birds, dogs, cats and the lesser carnivores that prey upon it.

The UFAW Handbook 6th edition says European hamsters are capable of inflicting serious bites but that at the Hannover medical school they have been tamed by frequent handling and personal attention to individuals such that ‘a large degree of tameness can be achieved in successive generations’. That is also true of the other hamsters kept as pets and in labs, the Syrian, Chinese and Djungarian but the European is that much bigger and a braver (wo)man than me would be needed to start the process.

European Hamsters and Maize Fields. A Nutritional Route to Local Extinction?

I have not seen a European Hamster (Cricetus cricetus) in the wild despite having twice looked for them at dusk in a hedgerow in Hungary where they had previously been seen—a classic case of, ‘if only you had been here last week’.

In the west of its range, notably in France, the hamster has declined markedly over the past decades. All sorts of reasons have been suggested, most to do with changes in agriculture. A recent paper1 by Mathilde Tissier, Yves Handrich, Odeline Dallongeville, Jean-Patrice Robin and Caroline Haboldfrom of the University of Strasbourg has suggested a nutritional reason for that decline. Previously members of that team had found an association between the decline of the species in France, where it was common on agricultural land, and the increase in the growing of maize by farmers2.

Observations of the hamster in the wild have indicated they feed on cereal crops, tubers and invertebrates. Hamsters hoard large amounts of food in their burrows and they hibernate. There is evidence that after hibernation female hamsters do not emerge from their burrows before their first pregnancy of the season, relying until then on their hoarded seeds. During gestation and lactation they emerge and supplement their diet of seeds with fresh plants like clover and invertebrates such as earthworms.

Using females from a captive colony of European Hamsters, the group first studied the effect of four different diets after emergence from hibernation: wheat+clover; wheat+earthworms; maize+clover; maize+earthworms. Similar numbers of young were born with all four diets. However, there was a marked difference in their early survival. On the wheat+earthworm diet, 80% of young survived to weaning while on the other three diets survival to weaning was under 12%. Clearly, something was missing from the diet; protein at about 18% of the diet one would guess with the clover supplement (compared with over 40% with earthworms). However, there was a clear difference between wheat and maize in terms of survival of the young.

At this point, human nutritionists would be bouncing up and down to tell you that there is a key difference between wheat and maize: the content and bioavailability of niacin (Vitamin B3 or nicotinamide) are much lower in maize and that, given the supply of earthworms rich in other nutrients that are relatively low in maize, the most likely nutrient lacking would be niacin.

The next season, a simple experiment was done. The maize+earthworm diet was compared with the same to which niacin was added. The results were clear. From a mean of less than two surviving until weaning with the maize+earthworm diet, supplementation with niacin increased that survival to over four.

The authors continued:

…regarding the European hamster, given that wild populations of this species are surrounded by 55–80% of intensively managed maize monoculture in Alsace (France), with sized field of 1.4 ha that corresponds to seven times the home range of a female, extremely low crop rotations (i.e. sometimes more than seven successive years of maize cultivated in the same plot) and high use of herbicides—dramatically reducing the proportion of adventive species—wild hamsters are undoubtedly constrained in their diet.

Now, you may ask, having demonstrated that nutritional deficiency can affect the survival of young hamsters to weaning, do the authors have any evidence that is a key cause of the decline of the species in France? In other words, do observations in the wild show the number of young emerging from the burrow, particularly from the first litter of the season, to be low?

The discursive paper (some of the data presented are irrelevant to the main story) which could have benefitted from a benignly dictatorial editor, raises several other questions. For example, nowhere I can see is any comparison made with data from the captive colony fed a presumably ‘complete’ diet. What was the litter size, survival to weaning etc. compared with the best performing experimental groups?

I must admit to being confused on the ‘normal’ litter size at birth of the European Hamster which is why a comparison with the breeding colony would have been informative. I have found value of 4-18 young, with numbers declining since about 19803. I have also found an account that there is a strong genetic element determining litter size in captive colonies4.

The reduction in litter size after parturition seemed to vary from a gradual loss on the wheat+clover diet, for example, to a complete lack of lack of maternal care in most of the animals on maize+clover. It is well known that if nutrition is inadequate or other environmental conditions are not right, female rodents kill and eat their young thereby conserving their resources to try again when the chances of producing fit young are better. Indeed a great deal of effort in he past went into devising diets for laboratory rodents, including hamsters, of course, to overcome such problems. So to those of us who have kept rodents the lack of maternal care in the malnourished hamsters was to be expected. However, true to form that British comic which masquerades as a newspaper, the Daily Mail, was on form when it picked up this story:

There is evidence in Syrian Hamsters that the sex ratio is manipulated after parturition by maternal cannibalism in different environmental conditions5. Having some proprietorial interest in mechanisms controlling the sex ratio in rodents, in my case the selective reabsorption of embryos in the Guinea Pig6, it would be of interest to know the sex ratio of the young surviving to weaning in the different experimental groups.

Again back in the real world, how many animals could be affected by niacin-deficiency from eating cultivated maize as a staple in the wild, Tissier et al. wondered. American Black Bears with young, as opposed to bears without young, avoid eating maize and other cultivated crops. They also suggested that bees could be adversely affected by feeding too heavily on maize pollen.


1 Tissier ML, Handrich Y, Dallongeville O, Robin J-P, Habold C. 2017 Diets derived from maize monoculture cause maternal infanticides in the endangered European hamster due to a vitamin B3 deficiency. Proc. R. Soc. B 284, 20162168.

2 Tissier ML, Handrich Y, Dallongeville O, Robin J-P, Weitten M, Pevet P, Kourkgy C, Habold C. 2016. How maize monoculture and increasing winter rainfall have brought the hibernating European hamster to the verge of extinction. Scientific Reports 6 25531 doi: 10.1038/srep25531

3 Surov A, Banaszek A, Bogomolov P, Feoktistova N, Monecke S. 2016. Dramatic global decrease in the range and the reproduction rate of European hamsters Cricetus cricetus. Endangered Species Research 31, 119-145 doi 10.3354/esr00749

4 La Haye MJJ, Koelwijn HP, Siepel H, Verwimp N, Windig JJ. 2012. Genetic rescue and the increase of litter size in the recovery breeding program of the common hamster (Cricetus cricetus) in the Netherlands. Relatedness, inbreeding and heritability of litter size in a breeding program of an endangered rodent. Hereditas 149, 207-216

5 Beer AK, Zucker I. 2012. Sex ratio adjustment by sex-specific maternal cannibalism in hamsters. Physiology & Behavior 107, 271-276 doi: 10.1016/jphysbeh.2012.09.001

6 Peaker M, Taylor, E. 1996. Sex ratio and litter size in the guineapig. Journal of Reproduction and Fertility 108, 63-67

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.