Tuesday 27 April 2021

R Maxwell Savage: The Forgotten Doyen of British Ecological Herpetology Part 4: The Smell of Algae

Maxwell Savage’s big idea was that Common Frogs are attracted to ponds for breeding by the odour emitted by algae in the water. This phenomenon, he argued, would explain the timing in response to earlier rainfall, the preference for one pond over another, why frogs do not spawn in every pond and why frogs may spawn in a pond one year but not the next.

His hypothesis was based on his earlier observations on the food, or at least the gut contents, of tadpoles of which algae formed a large part; no point in spawning in a pond with no algae. In addition he found that frogs spawned in ponds with higher phosphate and potassium concentrations, in other words water ideal for the growth of plants. He suggested that in summer ‘higher’ plants grow rapidly and deplete the water of minerals. Runoff from rain in the winter then carries minerals, particularly phosphate, into the ponds which then leads, with increasing length and intensity of daylight, to an algal bloom and it is the smell of the algae that frogs take as their cue to migrate to the source of the odour. In essence he provided an explanation for the effects of amounts of rainfall in the months before spawning on the timing and direction of migration as well as the choice of pond.

Cartoon illustrating Maxwell Savage's hypothesis 

Savage realised that a problem arose with frogs moving to ponds against the direction of the wind. He suggested that various physical phenomena involving different movement of air at ground level, in ditches which frogs often use to reach ponds, and eddying could overcome the objection.

Savage further argued that it is possible to dispense with some substances in or produced by ponds as possible attractants. The first is water itself or the direct effect of rainfall since many frogs hibernate in ponds or very damp surroundings from which they migrate to a breeding pond. Then there were carbon dioxide (ubiquitous), ammonia (frogs would be ‘drawn to manure heaps’) and hydrogen sulphide (probably not released into the air), methane (again ponds would not be the only source). Instead he firmly came down on the side of volatile organic compounds produced by algae:

…It is, however, not the higher plants that do this [impart the characteristic of pond water], but the algae. There is much information on this matter, for it is of economic importance. If certain species of algae grow in drinking-water reservoirs to too large an extent, the consumers complain that the water tastes or smells. The odours are not always unpleasant, but people do not like water that has a strong smell or taste, whatever it is. The odours are due to essential oils elaborated by the algae, and the smells are so characteristic that a skilled person can detect and identify the species of alga sometimes before it can be located under the microscope. I once detected a smell from a pond (Large Totteridge) many yards from the bank, and suspected from the textbook description that it was due to Synura livella[*]. Micro­scopic examination showed that this species was abundant in the water 

     The fit of this hypothesis with most of the facts in the field is very good. The smells are found in ponds—nowhere else in the whole countryside. Any particular smell is probably only found in a few ponds for there are so many species of algae that, in a limited area, there are hardly any two ponds with the same flora. Ponds tend to have the same species in successive years, but this is not invariably so…

The observational and statistical associations that Savage unearthed make a compelling case for the central role of aquatic algae; they tie everything together. As good as Savage was in observing and drawing evidence from lots of different fields into a plausible hypothesis, the fact remains that there have been no experimental tests of what remains a fascinating possibility at least and a high probability at best.

There are two points to stress at this stage. The first is that Savage’s hypothesis concerns one species, the Common Frog, Rana temporaria. Various species of amphibian are now known to use a variety of mechanisms for navigation during migration. The evidence that frogs head for the pond in which they grew as tadpoles as their breeding pond (‘homing’) now seems to be strong and it is here that evidence suggests that Savage’s algal hypothesis cannot be the whole story. I have seen frogs accumulating on the earth of three filled-in ponds at the normal time of breeding; in two cases spawn was laid with no hope of its survival. (A similar phenomenon has been observed in toads.) Were these frogs that had not strayed far and using a local memory map to return home? Would frogs from further away not have been drawn to the bare earth of a filled-in pond?

Savage was clearly disappointed by the reception given to his hypothesis while realising the difficulties in taking things further, as demonstrated by the following extract:

It would be quite wrong to conclude this chapter leaving the reader with the impression that the algal hypothesis has been universally accepted. In fact, it is probably true to say that the general attitude has been one of polite incredulity…


Frogs live their aquatic life invariably among algae, which dominate the life of a pond. It has been said that if all the higher plants in a pond were to be removed and replaced by glass models of the same shape and size, the animal life in the pond would go on just the same. Re­move the algae, and life would be vastly different. Knowing the number of parallels between the behaviour of frogs and the behaviour of algae, and that no two essential oils have the same chemical com­position or the same smell, I have always thought the hypothesis suffered from the difficulty of proof, rather than from any improba­bility. But there is no need to despair. After all, it was only in late 1957 that we had experimental proof that satellites were kept in their orbits by gravitation. Up till then the whole thing had been a hypo­thesis, based on a number of parallels! 

What Savage did not deserve was to be ignored by many of those who came after him. For example, in one chapter of a book published in 2005 which I will not name since it does not deserve even adverse publicity, Savage does not get a mention even though such factors as rainfall and odours in triggering spring migration in amphibians are discussed at considerable length. Like Trevor Beebee before me I find the omission of Savage—and not just in that one case—both astonishing and inexcusable.

However, all is not last since last week the popular BBC programme Countryfile included an item on frogs and a contributor said they were attracted to their breeding ponds by the smell of algae.

In the next article I will discuss how Maxwell Savage tried in his final research paper to take his algal hypothesis further but had to swap species in order to do so.

*the smell of Synura and the chemical composition of the odours produced is described in this YouTube video.

Wednesday 21 April 2021

R Maxwell Savage: The Forgotten Doyen of British Ecological Herpetology Part 3: His 1961 Book on the Common Frog

Ronald Henry Maxwell Savage’s book, The Ecology and Life History of the Common Frog (Rana temporaria temporaria) was published in London by Pitman (1961) and in the USA by Hafner, New York in 1962. An online version of the USA edition can be found here; this version is also offered for sale as a ‘print’ version of bound photocopied pages with the claim that the work is in the public domain. With Savage having died in 1985, i.e. 36 years ago, the work is still, as I understand the law, under copyright in the UK and also I suspect in the USA.

It has proved an interesting exercise to re-read the book after first reading it more than than 55 years ago. I have also been able to compare my impressions with reviews written at the time. I am reproducing those reviews here because while recommending strongly that it should still be read by those working on amphibians as professionals or amateurs it is useful to consider what contemporary reviewers thought of it and its various strengths and weaknesses. I have found four reviews in searches; each has important things to say

The most extensive review was that written by Richard George ZWEIFEL (1926-2019) of the American Museum of Natural History for Copeia:

Dr. Savage has concentrated most of his research effort for more than 30 years on the ecology in the British Isles of this one species of frog. This book is in large part a compilation of the results of research reported in a series of papers that com­menced in 1935. although new data are presented and old data are in some instances re­-examined and reinterpreted. It is most worth while to have this published material and new information assembled in one narrative. 

The author's concept of ecology cuts across a broad spectrum of scientific disciplines and he is ready to delve into any subject that may illuminate some phase of the life of his chosen animal. Thus, illustrating his ap­proach. we find material on the biochemistry of the jelly of the frog's egg, experiments on the behavior of young tadpoles in relation to water deficient in oxygen, observations on the relationship of gut contents to growth rate in tadpoles (how much of what a tad­pole consumes is really food?), statistical in­vestigation of density of internal parasites as a measure of mortality (from causes other than parasites) in tadpoles, and an analysis of the relationship of direction of wind to the number of frogs migrating to the breed­ing ponds, to mention just a few of many topics lucidly presented. 

The book is arranged in ten chapters, nine of which treat various aspects of the ecology and life-history of the frog, beginning with eggs and young tadpoles and going lull cycle to breeding behavior. The tenth chapter discusses statistical and other methods of study. An appendix treats in detail statistical aspects of problems dealt with in earlier chapters and a second appendix consists of a glossary. 

The longest chapter of the book is devoted to investigation of the influence on the date of spawning of variables in the external environment. Voluminous data on spawn­ ing dates (collected by volunteer observers cooperating with the Royal Meteorological Society) were available to Savage, who ex­amined the data statistically for possible correlations of weather with variation in spawning dates at different localities and in different years. The weather data used are those recorded at Government weather sta­tions, but Savage is well aware that his ani­mals do not live in weather instrument shelters. He points out that as long as there is reasonably good correlation between varia­tion at the instrument site and in the ani­mal's habitat he can make statistically valid use of the available data. Erroneous inter­pretations are not likely to result, and only low correlations of weather and behavior will be obscured. Nevertheless, when Savage can cite temperatures of spawn as different as 15° and 2I.5°C on the same day in the same area (but in different ponds) one cannot help but wish that data had been gathered somewhat closer to the microhabitat of the animals. 

The analysis of single elements of weather in relation to spawning offered little enlightenment, for Savage observed in the field and confirmed over the calculator that neither rainfall nor temperature alone correlated closely with date of spawning. When he studied the effects of climatic variables act­ing together, however, he uncovered signifi­cant correlations. The data were analyzed by means of "Joint functional regression dia­grams,” three-dimensional graphs in which isophenes representing spawning dates mean­der across a grid with two weather vari­ables (chosen in various combinations from monthly mean temperature, monthly mean rainfall and percentages of possible sunshine) on the axes. These laboriously constructed diagrams illustrate well the complex inter­ actions of the various environmental influences and make it apparent why analysis of single factors gave meager results. 

Another chapter deals with food, hiberna­tion. and migration. Little space is devoted to food. Savage tabulates the stomach con­tents of 17 frogs and provides additional data from the literature to contrast the food of Bufo and Rana. The conclusion that differences in food habits between the spe­cies are related in part to habitat differences between frogs and toads—“they eat what hap­pens to be there”—is certainly sound, al­though the suggestion that “Anura in general are not indiscriminate feeders" may raise some questions, depending upon how broadly one interprets “indiscriminate." There is certainly little evidence for taxonomic discrimination. For example, a recent paper by Inger and Marx (Exploration du Parc Na­tional de l’Upemba, fasc. 64, 1961) shows that a majority of the African species they studied had eaten representatives of three or four phyla. Referring to Bombina variegata in captivity, Savage states “They reject mealworms." citing this as an instance of animals being most ready to feed on prey they are most likely to find in their natural habitats. But the Bombina I  have kept for several years, orientalis and bombina as well as variegata, would long ago have starved had they rejected mealworms. 

Savage presents some information on hiber­nation sites, hut devotes the bulk of the chapter to a discussion of migration to the breeding ponds and the hypothesis that the characteristic odor given a pond by its algal flora is detected at a distance and guides the frogs to the proper pond. No effective chal­lenge to this hypothesis has been made since it was first presented many years ago, and the evidence for similar phenomena in anadromous fish returning to the stream in which they hatched and for homing in newts adds credibility to the hypothesis. 

This is a stimulating book and the reader will find himself comparing the behavior of Rana temporaria with that of the frogs he knows, mentally testing Savage's explanation against the actions of other species. Parallels between the European species and its North American relative Rana sylvatica are partic­ularly striking. The paragraphs describing the relatively brief appearance of adult frogs at the breeding ponds very early in the year, the concentration of egg masses in a shallow, restricted part of the pond, the swarming of newly hatched tadpoles atop the disintegrating masses of jelly all could have been written about sylvatica. It is only when Sav­age tells us that temporaria avoids wooded areas that we note a marked difference from the habits of the wood frog. 

A facet of the work disappointing to me is the slight use made of the marking-recap­ture technique of study. Savage makes his feelings plain: "I believe that the animals being studied should receive as little inter­ference as possible, for as soon as one does anything to them, they are no longer ‘at home.' By all means use any laboratory methods to study the environment, but leave the animals themselves alone." One can deduce growth rates, movements and sur­vivorship bv a variety of ingenious methods, but the concrete evidence provided by marked animals is often best. Savage did utilise paper tags for temporary marking of some animals, and some of the data most interesting to me were derived from these ani­mals. One frog tagged in its hibernating pond was recaptured in a breeding pond and thus verified (as no other data could have) one source of the breeding population of this particular pond. 

The records of 52 tagged frogs in one local population prevent a fascinating picture of the fluctuating composition of that popula­tion during the breeding season. On any night the tagged males outnumbered the tagged females, sometimes by as much as six to one, and among tagged individuals there were almost twice as many males as females. Males tended to remain at the bleeding pond for several days in succession, or return after disappearing for one or more days, whereas females in this instance were not in attend­ance for more than one night. Savage tells us that the number of the sexes are about equal, so the unbalanced sex ratio probably merely reflects the male habit of spending several nights in the pond. (Tenacity can have its rewards: male No. A18 mated with different females three nights in succession.) 

Savage concentrated his study at the breed­ing ponds, and consequently offers very little concerning the life of the frogs during the period when they are neither breeding nor hibernating. A chapter only two pages in length covers the life of the juvenile frog. Estimates given of three to six breeding frogs per acre are based on the number of egg masses counted in the ponds, but we are not told how the author knew the extent of the area served by each pond. Surveys of a large number of ponds showed that no pond served as a breeding site every year. What happens to the frogs when a pond is de­serted? An intensive marking program might provide an answer. 

The author makes broad hut somewhat spotty use of the literature. Thus, as an ex­ample of geographic variation in embryonic temperature tolerance, he cites the work by Volpe on Bufo americanus but not the work of Moore on Rana pipiens. Again, he cites without critical comment a report that the eggs of a species of Rana have a thermal death point of 45°C. a figure far higher than reported for any anuran whose eggs have been adequately studied. A purely personal feeling, but one that I expect is shared by many readers, is a dislike for the abbreviated style of litera­ture citation used (probably favored by pub­lishers because of saving in type setting) and for grouping of citations at the close of each chapter. I much prefer to see titles cited in full and to have the references in one place. 

A brief review cannot do justice to the years of effort and enlightened inquiry that went into the research, nor can it touch on more than a few of the subjects explored in the book. Anyone interested in the ecol­ogy of amphibians will profit from reading it; I recommend it highly. 

The following was written for Journal of Animal Ecology by Thomas Townley MACAN (1910-1985) while at the Freshwater Biological Association:

It is a commonplace idea that a distribution map should not be studied unless something is known about the distribution of the collectors from whose data it is compiled. More novel per­haps is the suggestion that a general ecological work should not be studied without some know­ledge of the author. Dr Savage writes in the foreword that he has been working on frogs for 30 

years, his degrees and where he took them are set out on the page before, and that is all the information there is about him. What sort of job has he held during the 30 years? What facilities in the way of collaborators and apparatus did it provide? How much time was he able to devote to frogs? What influenced him to follow certain lines in preference to others? These are some of the questions that readers may ask. As this is a pioneer work of its kind, and ecologists may learn from what Dr Savage did not achieve as well as from what he did, answers would have been useful. 

The author has been chiefly concerned with the factors that affect the date and place of oviposition and the behaviour before and during the process, but in the course of the 30 years he has investigated many other aspects of the biology of the common frog. These observations, together with those, often few and unimportant, of other workers are the subject of the first eight chapters. How much remains to be found out is striking; that is not a disparagement of Dr Savage's achievement but a demonstration of the length of time that work of this kind takes. The distribution of the species is established, but no explanation of the limiting factors is yet available. It is known what tadpoles eat, but not from what they derive nourishment, which makes a gap in any discussion about the factors limiting sizes of populations. The sizes of adult populations and the factors that limit them are also in need of further study.

Not until about the middle of the book does Dr Savage reach the work which has been his main interest. Fig. 20 is a map of the British Isles covered with ‘isophenes', lines drawn through places where the spawning date is the same. In a small area of South Wales and of North Devon, and in the south of Ireland, spawning is in January; to be exact, before 30 January which is day 30. Spawning between days 31 and 40 is also confined to the south and west. Late spawning, between days 71 and 80, is a phenomenon of the east side of England and the midlands. The latest spawning, after day 100 (10 March), is in the Pennine area. Incidentally this map is not accompanied by any information about how the data was gathered, nor on how many observations each isophene is based. 

In general the earliest breeding is found in places with the highest rainfall. Temperatures near freezing-point a month before spawning are associated with early spawning at a lower rainfall than at higher temperatures. When the weather two months before spawning is examined, early spawning is found to be associated with temperature above 6°C and is not greatly affected by rainfall. Light also plays a part. It is surmised that these climatic factors react on the frog through one or several species of algae, an outburst of which stimulates spawning. Some readers will be disappointed to find that there is still this big gap to be bridged by theory only, but the author argues cogently in support of the line he has chosen to pursue.

I am not competent to pass an opinion on the joint functional regression diagrams and the statistical methods on which these conclusions are based, but my colleague, Miss C. Kipling, praises them. Anyone interested in the factors governing any regular event such as oviposition or emergence is likely to find Dr Savage's method worth study. 

There is a danger that some readers, put off by the incompleteness of the earlier chapters, will lay the book aside before they reach the author’s main work. On the other hand it is valuable to have this scattered information brought together in one place. Many will be grateful to Dr Savage for bringing it together, and he is to be congratulated on the amount that his own researches have contributed and on the fair way in which he has written about what is known and what is not known. 

The following review for The Naturalist appeared over the initials E.B. Since the journal was based in the University of Leeds I soon found that the reviewer was Edward BROADHEAD, then senior lecturer in zoology and an expert on psocids, insects on which my ignorance is total:

This book is an account of the research, carried out by the author as a recreation, on the ecology of the common frog. It covers all stages of the life history egg, tadpole, juvenile and adult frogs and much information is brought together on parasites, distribution and breeding behaviour. The section on the relation between spawning dates and weather in chapter 8 is new and of great interest, and a full account of the method used and of other statistical methods in chapter 10 adds considerably to the value of the book.

 The book is written in a chatty and enthusiastic style. The author's work is recorded in great detail and with a wealth of comment and discussion, but the book would have been improved by a better balance. The work of others is mentioned but never in the detail accorded to the author’s own papers, and very often the comment and discussion on some of the factual material presented is excessive, much space being given in some places to pure conjecture as, for instance, on pp. 79 et seq. where density dependence is discussed. 

Finally, my old friend ‘Amo’, Emmanuel Ciprian AMOROSO FRS (1901-1982), wrote the following for New Scientist. He, I think, had met Savage at Zoological Society of London meetings. Amo had recently worked on the ‘marsupial frog’ Gastrotheca marsupiata while professor at physiology at the Royal Veterinary College.

Maxwell Savage has been interested in the Common Frog and its tadpoles for a long time and he has courageously undertaken to write this account of their lives. Nor does he speak only as a compiler; his 30 years of research on the amphibia qualify him unusually well for the undertaking. The material is organized in 10 chapters and in these the student of behaviour should find as much of interest as the ecologist, for examples of observed be­haviour under a wide range of circumstances are given liberally. The general biologist should appreciate the information presented on reproduction, growth, mor­phology and like topics, while students of population may note outstanding factual contributions and unanswered questions alike. 

The author is at his best when he is talking about the riddle of migration and his claims for his algal hypothesis are modest. The book not only solves many of the mysteries surrounding the movement of the frogs to the ponds but is also replete with facts about their life history and behaviour. It is unfortunate, however, that only a small group of specialists will be able to profit properly from this work, as several defects reduce its value for a wider audience. The organization is loose and the more outstanding highlights of the re­searches are swamped in the telling by redundant detail; it is thus difficult to use the volume for reference. Furthermore, each section seems to be addressed to those who already know that field and its history rather thoroughly. Perhaps the author will reply that he intended his book for just such an audience. If so, it is a very limited one; and it may be questioned whether any­one with so great a grasp of the subject will not have made a similar synthesis for himself already. 

Altogether, while one familiar with Savage's work will find here little that is wholly new, there is a vigour and a modi­cum of fresh thought that is stimulating and as a summary of Savage's thinking the book is valuable. 

 I can add very little to those reviews other than to point out that while some of the discussions are  to modern eyes completely beyond their sell-by-date (matters physiological for example) and, as I remarked in the first article of this series, errors were made in drawing the statistical material together, the whole approach that Savage took (‘he is ready to delve into any subject that may illuminate some phase of the life of his chosen animal’, as Zweifel put it) shines through.

Savage did himself a disservice by not adding some biographical information and the circumstances under which he operated as a part-time herpetologist. While the research, like any other, has to be judged on its merits regardless of the circumstances of the person doing it, I do think some information would have added greatly to the interest in his work and to a much deeper appreciation of his devotion to his pursuit. I also think Amo hit the nail on the head by recognising the difficulty the average reader would have in reading the book and in implying that hard editing would have been of great benefit; there the publishers were amiss in not insisting on it. Savage, though, answered the question of who the book was intended for in the first paragraph of the Preface: ‘I wrote the book for myself’.

In the next article I discuss Savage’s big idea and the evidence he gathered.

Amoroso. EC. 1961. Book Review. The Ecology and Life History of the Common Frog by R. Maxwell Savage. New Scientist 12 (23 November 1961), 511-512.

EB. 1961. Book Review. The Ecology and Life History of the Common Frog by R. Maxwell Savage. The Naturalist 1961, 35.

Macan TT. 1962. Book Review. The Ecology and Life History of the Common Frog by R. Maxwell Savage. Journal of Animal Ecology 31, 398-399.

Zweifel RG 1962. Book Review. The Ecology and Life History of the Common Frog (Rana temporaria temporaria) by R. Maxwell Savage. Copeia 1962, 667-669.

Thursday 15 April 2021

The Frog Man. R Maxwell Savage: The Forgotten Doyen of British Ecological Herpetology Part 2

R. Maxwell Savage
from Beebee 2010

In my last post I described the work done by R. Maxwell Savage on the relations between local climate and weather on the time of annual spawning of the Common Frog, Rana temporaria, in Britain. I also noted that I was delighted to find that Trevor Beebee, who found reference to Savage’s often seminal work on amphibians lacking and information on his life absent, had launched an appeal for information. As a result a biography appeared in Herpetological Journal in 2010, 25 years after Savage’s death. More information on Savage’s professional life has emerged and it throws considerable light on the approaches Savage took in studying the Common Frog at all stages of development, from the formation and workings of frog spawn and the life of the tadpole to the triggers for breeding. 

There cannot be many scientists who have had papers in Nature for their amateur as well as their unrelated day job. For that matter, there cannot be many scientists who have received research grants from the Royal Society and a PhD for their spare-time pursuit. R. Maxwell Savage had all of these distinctions as well as the Stamford Raffles Award from the Zoological Society of London in 1967.

Ronald Henry Maxwell Savage* was born in Wood Green, London, on 2 May 1900, the third child of the company secretary of an explosives company. The Savage family had a coat of arms and Savage appears in Fox-Davies’s book, Armorial Families†. From Queen’s College Cambridge (1918-21) he graduated in Natural Sciences. He was a chemist and worked for his entire professional life, 1921-1965, for S. Maw Son & Sons at Barnet in Hertfordshire. Founded in the 1820s the company manufactured surgical instruments, medical kits, as well as common pharmaceuticals, at a large factory built when the form outgrew its London premises. eBay has products made by Maw: infant feeding bottles; bedpans; invalid cups; inhalers; toothpaste; surgical gear and bandages. Field dressings were supplied to British and allied forces and, from published papers, dressings were a particular concern to Savage from the 1930s to the 1950s. Some of the testing and improvement of surgical dressings was done in collaboration with surgeons at the London teaching hospitals. Means of sterilizing dressings, the performance of thrombin-containing dressings designed to speed up blood-clotting and improving the absorbency and holding capacity of dressings were the subjects of some of the papers Savage published in medical journals. He was also involved in the use of chlorophyll as a deodorant—a craze for a while in the 1950s when we had chlorophyll toothpaste, chewing gum, soap, shampoo, lotions etc. With arguments raging on the efficacy of some of these products Savage demonstrated, using proper test procedures and statistical analysis, that ‘chlorophyll on cotton pads does reduce the odour of decomposing blood, the probability of our results arising by chance being less than one in 2,000 million’.

Savage was, in short, the epitome of the brave new world of industrial research in the 1930s. 

His approach to the development and improvement of products, was quantitative, experimental and observational; it included bioassays, testing and quality control that depend on rigorous statistical treatment. It is these attributes that he carried over into his research in the field and in his home laboratory on the Common Frog and other amphibians. He did experiments and used statistical techniques on his field data that put him years ahead of his time—and in so doing probably made much of his work incomprehensible to biologists of the day. I can just imagine the expression on the faces of those who listened to the papers he gave at the Zoological Society in the 1930s. Members of the audience would not, to put it politely, have been familiar with the concepts he presented. It is perhaps not surprising that he complained that his work had been met with ‘polite incredulity’.

I have made a list of his publications from his day job and of those on his research on amphibians;  it is appended below.

In the 1939 Register, the emergency census taken as preparation for war, Savage was living with his wife and incapacitated mother at Derwent Avenue, Mill Hill. He is described as ‘Chemist: analytical and research. Works Manager: surgical dressings’. He was chief chemist for Maw Son & Sons. It was the field dressings made by Savage’s team that were issued to soldiers in the field as ‘First Field Dressing’ packs that could be brought out of a battledress pocket and applied quickly to a bullet or shrapnel wound. Maws supplied many of the field dressings, first aid kits and surgical dressings to military and civil defence organisations and it is clear that as Savage’s research on surgical dressings went on into the 1950s that he was seeking continuous improvement in the company’s products.

British Army First Field Dressing Pack
by S Maw Son & Sons

Savage wrote of how he first became interested—and how that interest was encouraged—in research on amphibians. As a young man he came back from a holiday in France with some Yellow-bellied Toads, Bombina variegata. He was encouraged by Hampton Wildman Parker (1897-1968) then in charge of reptiles and amphibians at the Natural History Museum in London to publish some of the observations he had made and to do more. Savage noted the incongruity of a taxonomist encouraging research which was far from taxonomic but Parker was a Cambridge graduate, like Savage, in natural sciences which included biological subjects and chemistry. It seems possible that they had met in Cambridge because Savage graduated in 1921 and Parker (although three years older) in 1923. The paper on B. variegata was published in 1932 in Proceedings of the Zoological Society (PZS), since retitled Journal of Zoology.

Throughout the 1930s and beyond he published a string of papers on the Common Frog, mainly in PZS. I will not dwell on what he did in this article since I shall write follow-ups on specific aspects, including his book which pulled together his earlier work, as well as on his main hypothesis which occupied much of his time over the next 40 years.

This might though be a good place to put his huge amount of fieldwork in context. In his words:

The area lay on the borders of Middlesex and Hertfordshire, and covered about eighty square miles. Within this area 92 ponds were kept under observation over a period of ten years. None were observed for the whole of this time, for most of the observations were made between 1934 and 1938, although less systematic observations were maintained for another twenty years afterwards, and some of the ponds were known for twenty years before.

The ponds were within driving distance of where he lived, first in Mill Hill and then Hadley Wood.

The approximate area containing the 92 ponds studied by Maxwell
How many survive?

His work on tadpoles was written up for his University of London PhD thesis, The Ecology of Anuran Tadpoles, at Birkbeck College. The date given in the library catalogue is 1950-1951.

Both Savage and Louis Lantz were industrial chemists who worked, as amateurs, on herpetological matters in England. It is evident from Savage’s papers that they were in regular contact. Indeed, Savage collected Painted Frogs for Lantz on the French island of Port-Cros. He was in regular contact with Burgess Barnett—with whom he shared an interest in the mechanism of blood clotting—over the solidification of frog spawn after laying. We also know that Deryk Frazer helped him with summarising phenological data. When Savage was looking at the feeding mechanisms of tadpoles, Laurence Cooper Stuart (1907-1983) of the University of Michigan sent him specimens of a microhylid. Other names are mentioned in his book and it is clear that he was connected with all the key players in his areas of interest, in his ‘amateur’ as well as in his professional life.

Savage thanked his wife, Violetta, née Hetherington, whom he married in 1931 for helping him with fieldwork in the 1930s; they were married in 1931. He also thanked a Dr W.F. Purdy (also acknowledged in one of his papers from Maw Son & Sons) for help with transport and advice on presentation of the figures, and a Mr A. Edwards; I have been unable to find any information on either.

Trevor Beebee mentions that Savage from the 1920s onwards travelled widely on holidays in continental Europe. The fire-bellied toads from France I mentioned above which started his research activity were one obvious result of his travels as were the painted frogs sent to Louis Lantz.

Savage was a Fellow of the Royal Institute of Chemistry and of the Zoological Society of London. He became a member of the British Herpetological Society soon after its foundation in 1947, and was one of my predecessors as editor of its journal, the British Journal of Herpetology (now Herpetological Journal).

On retirement the Savages moved from Hadley Wood to Welwyn where Ronald Maxwell Savage died in 1985.

In the next article in this series I will discuss his book and its reception before moving on to discussion of his big idea, some of his earlier research and of his studies on Xenopus.

†Argent, on a fesse dancetté between four lioncels three in chief and one in base sable, two doves each holding in the beak a branch of olive proper. Mantling sable and argent. Crest—On a wreath of colours, in front of a lion’s jamb couped or, grasping a branch of holly fructed proper, a saltire sable. Motto—“A te pro te”. That coat of arms (a variant of those by branches of the Savage family) appears to have been granted to Henry Maxwell Savage (1861-1938) in 1918.

*He seems to have dropped H[enry] from his initials; he always published under the name R. Maxwell Savage.

Beebee TJC. 2010. Ronald Maxwell Savage, 1900-1985: a tribute. Herpetological Journal 20, 115-116.

Ronald Henry Maxwell Savage

Publications and Radio Broadcasts


Note that the volume numbers of Proceedings of the Zoological Society are ones currently listed on the ZSL publication website. Various other methods of numbering the volumes were used in the past and may be encountered in Savage’s own papers and book.

Savage RM. 1932. The spawning, voice, and sexual behaviour of Bombina variegata. Proceedings of the Zoological Society of London 102, 889-898.

Savage RM. 1934. The breeding behaviour of the common frog, Rana temporaria temporaria Linn., and of the common toad, Bufo bufo bufo Linn. Proceedings of the Zoological Society of London 104, 55-70.

Savage RM. 1935. The influence of external factors on the spawning date and migration of the common frog, Rana temporaria temporaria Linn. Proceedings of the Zoological Society of London 105, 49-98.

Savage RM. 1935. The ecology of young tadpoles, with special reference to some adaptations to the habit of mass‐spawning in Rana temporaria temporaria Linn. Proceedings of the Zoological Society of London 105, 605-610.

Savage RM. 1937. The ecology of young tadpoles, with special reference to the nutrition of the early larvae of Rana temporaria temporaria Linn., Bufo bufo bufo Linn., and Bombina variegata variegata Linn. Proceedings of the Zoological Society of London 107, 249-260.

Savage RM. 1939. The ecology of young tadpoles, with special reference to carbohydrate changes in development, and to the function of the envelope. Proceedings of the Zoological Society of London 108, 465-480.

Savage RM. 1939. The distribution of the spawn-ponds of the common frog, Rana temporaria temporaria Linn., over a portion of the London clay and associated drift. Proceedings of the Zoological Society of London 109, 1-19.

Savage RM. 1942. The burrowing and emergence of the Spade‐Foot Toad, Pelobates fuscus fuscus Wagler. Proceedings of the Zoological Society of London 112, 21-35.

Savage RM. 1950. Observations on some natural epizootics of the trematode Polystoma integerrimum among tadpoles of Rana temporaria temporaria. Proceedings of the Zoological Society of London 120, 15-37.

Savage RM. 1952. Malcolm Smith (1951). The British Amphibians and Reptiles [book review]. Journal of Animal Ecology 21, 162-163.

*Savage RM. 1952. Ecological, physiological and anatomical observations on some species of anuran tadpoles. Proceedings of the Zoological Society of London 122, 467-514.

Savage RM. 1955. The ingestive, digestive, and respiratory systems of the microhylid tadpole Hypopachus aguae. Copeia 1955, 120-127.

Savage RM 1956. Thermal function of the envelope of the egg of the common frog Rana temporaria, with observations on the structure of the egg clusters. British Journal of Herpetology 1, 57-66.

Savage RM. 1961. The Ecology and Life History of the Common Frog (Rana temporaria temporaria). London: Pitman.

Savage RM. 1963. A speculation on the pallid tadpoles of Xenopus laevis. British Journal of Herpetology 3, 74-76.

Savage RM. 1965. External stimulus of the natural spawning of Xenopus laevis. Nature 205, 618-619.

Savage RM. 1971. The natural stimulus for spawning in Xenopus laevis (Amphibia). Proceedings of the Zoological Society of London 165, 245-260.

*Footnote to this paper: This paper has been condensed from part of a thesis approved by the University of London for the degree of Ph.D


Savage RM. 1936. Penetration of heat into surgical dressings. Chemist and Druggist 125(2943), 14.

Savage RM, Chambers WP. 1938. Optimum temperature of formation of a blood clot. Nature 141 287-288.

Savage RM. 1940. Sterility tests on surgical dressings. Quarterly Journal of Pharmacy and Pharmacology 13, 237-251.

Savage RM. 1942. The sterilization of paraffin surgical dressings. British Medical Journal 1942(1), 472-474.

Savage RM. 1944. The sterilising action of steam admixed with air and other gases. Chemist and Druggist 142(3362), 73.

Savage RM. 1945. The sterilisation of surgical dressings. Pharmaceutical Journal 1945, 254.

Chambers WP, Savage RM. 1945. A comparison of methods of analysis of euflavine gauze with observations on the effect of sterilisation. Quarterly Journal of Pharmacy and Pharmacology 12, 237-234.

Savage RM, Bryce DM, Elliott JR. 1952. The water retention coefficient of surgical dressings. Journal of Pharmacy and Pharmacology 1952 4, 944–958.

Bryce DM, Savage RM. 1953. A note on surface-active agents and surgical dressings. Journal of Pharmacy and Pharmacology 5, 911-915.

Bryce D, Savage RM. 1953. Chlorophyll. British Medical Journal 1953(1), 833.

Savage RM. 1954. The sterilization of surgical dressings. Journal of Applied Bacteriology 17, 278-285.

Savage RM. 1954. A statistical study of variation in surgical dressings. Journal of Pharmacy and Pharmacology 6, 843-858.

Savill A, Daynes G, Savage RM. 1956. Bread. Lancet 267, 1071.

Savage RM. 1957. Sterilization of dressings. British Medical Journal 1957(2), 235.

Savage RM. 1962. Sweetened dummies. British Medical Journal 1962(2), 801.

Radio Broadcasts

3 February 1956. Naturalists’s Notebook. Edited by Maxwell Knight. Produced by Brandon Acton-Bond

8 March 1959. The Naturalist. BBC Home Service. Introduced and edited by Maxwell Knight. Produced by Jeffery Boswall