Animal Coloration (book)

Animal Coloration, or in full Animal Coloration: An Account of the Principal Facts and Theories Relating to the Colours and Markings of Animals, is a book by the English zoologist Frank Evers Beddard, published by Swan Sonnenschein in 1892. It formed part of the ongoing debate amongst zoologists about the relevance of Charles Darwin's theory of natural selection to the observed appearance, structure, and behaviour of animals, and vice versa.
Beddard states in the book that it contains little that is new, intending instead to give a clear overview of the subject. The main topics covered are camouflage, then called 'protective coloration'; mimicry; and sexual selection. Arguments for and against these aspects of animal coloration are intensively discussed in the book.
The book was reviewed in 1892 by the major journals including "The Auk", "Nature", and "Science". The scientist reviewers Joel Asaph Allen, Edward Bagnall Poulton and Robert Wilson Shufeldt took up different positions on the book and accordingly praised or criticized Beddard's work.
Modern evaluation of the book is from a variety of perspectives, including the history of Darwinism, the history of the Thayer debate on the purpose of camouflage, the mechanisms of camouflage, sexual selection, and mimicry. Beddard is seen as having covered a wide swath of modern biology with both theory and experiment.
Context.
Beddard (1858–1925) was an English zoologist specializing in Annelid worms, but writing much more widely on topics including mammals and zoogeography. He also contributed articles on earthworms, leeches and nematode worms to the 1911 "Encyclopædia Britannica". His decision to write an accessible book on animal coloration falls into this pattern. Beddard wrote "Animal Coloration" at a time when scientists' confidence in Charles Darwin's theory of evolution by natural selection was at a low ebb. Beddard's book was part of an ongoing debate among zoologists about how far natural selection affected animals, and how far other forces – such as the direct action of light – might be the causes of observed features such as the colours of animals. Edward Bagnall Poulton's far more strongly pro-Darwinian book "The Colours of Animals" had appeared just two years earlier in 1890.
Approach.
Beddard explains in his preface that the book grew from his 1890 Davis Lectures given for the public at London Zoo. The book "contains hardly anything novel, but professes to give some account of the principal phenomena of coloration exhibited by animals." He also notes that since Poulton's recent book "deal[s] with colour almost entirely from the point of view of natural selection, I have attempted to lay some stress upon other aspects of the question." Similarly, because Poulton treated insects in some detail, Beddard chooses to give more attention to other groups, though "it is impossible not to devote a good deal of space to insects". The examples are mainly from Beddard's own observation of "animals that may be usually seen in the Zoological Society's Gardens", though he also introduces and quotes the work of other scientists, including Henry Walter Bates and Alfred Russel Wallace.
Illustrations.
The book has four colour plates by Peter Smit, who both drew and prepared the chromolithographic plates. Plate 1 is stated in the "List of Illustrations" "To face page 108", but as bound in the first edition it is used as a Frontispiece, facing the title page.
There are also 36 woodcuts (in black and white) in the text, though one of these, "Eolis and Dendronotus" is intentionally repeated as figures 10 and 19 to accompany the text in two places. The woodcuts vary from small line drawings on a simple white background (as in the diagrammatic figure 28 of "Psyche helix", and figure 34 of the winter moth) to page-width illustrations like figure 2 which shows ermines in winter pelage, in a realistic depiction with a detailed snowy scene in the background. The woodcuts are certainly by a number of different artists; many are unsigned, but figures 5 and 26 are signed "E.A. Brockhaus X.A" lower right (X=cut, A=Artist), while figure 29 is signed "GM" lower left, and figures 35 and 36 are signed "ES" lower left. Figure 2 bears a monograph "FR", lower left, and figure 7, of the penguin "Aptenodytes patagonica" is stated to be "from Brehm" ("Brehms Tierleben").
Structure.
"Animal Coloration" has a simple structure of six chapters in its 288 pages.
Reception.
Contemporary.
"The Auk".
The American zoologist and ornithologist Joel Asaph Allen reviewed "Animal Coloration" in "The Auk" in 1893. Allen notes Beddard's remark that the book contains hardly anything novel, so that it is mainly a review of previous theories, but welcomes it as a review of the state of knowledge together with Beddard's critical commentary. Allen notes that Beddard could have gone further in criticising Weismann and Poulton on colour changes, but is "glad to see [that Beddard] is willing to grant that the influence of an animal's surroundings may exercise a direct influence upon its coloration without the intervention of the agency of 'natural selection.'"
Allen praises Beddard's "commendable conservatism" in his discussion of camouflage, which he compares to the "credulous spirit" of other authors. Reviewing the chapter on warning coloration, Allen remarks that the great horned owl is known to prey on the skunk, showing that even such a disagreeably pungent animal can be subject to predation.
On mimicry, Allen is critical of Bates's theory, arguing that edible mimics (such as flies) are often not protected by resembling distasteful models (such as wasps). Allen notes that Beddard deals with many special cases "as of .. spiders mimicking ants, etc." and finds the arguments against any selective advantage from Batesian mimicry, and so against natural selection, somewhat conclusive. Finally, reviewing the chapter on sexual selection, Allen writes (knowing that Wallace largely rejected sexual selection)
Allen then makes some remarks, praising Beddard for the "fine vein of irony" that he uses of
"Nature".
The zoologist Edward Bagnall Poulton, whose work is referred to throughout Beddard's book, reviewed "Animal Coloration" in "Nature" in 1892. Poulton is critical of Beddard and other authors, defending Darwin's theory of natural selection as "the most generally accepted explanation of organic evolution" and insisting that in "case after case" the Darwinian explanation turns out to be correct.
"Science".
The white supremacist scientist Robert Wilson Shufeldt reviewed "Animal Coloration" in "Science" in 1892, praising it as a concise and useful summary of the subject. He admires Macmillan Publishers' handling of the book with its attractive wood-cuts and coloured lithographic plates. He is pleased to find many Americans in the index. He quotes Beddard's distinction between colour and coloration. He considers that the book brings readers fully up to date and even adds a few new ideas. He recommends the book to all working American naturalists.
"Popular Science Monthly".
The anonymous reviewer in "Popular Science Monthly" in December 1892 writes that Beddard has "made a book interesting to both the zoologist and the general reader." On protective coloration, "he raises the question whether as a matter of fact animals are concealed from their foes by their protective resemblances, and shows that there is much evidence on the negative side", and further that such colours are sometimes produced "more simply and directly than by the operation of natural selection." On warning colours, the reviewer notes that Beddard gives "much weight" to Eisig's theory that "the usual bright pigments" in caterpillars (accidentally) cause inedibility, "instead of being produced to advertise it" and that Beddard cautions against assuming that "the sight or taste of animals were the same as that of man".
Modern.
Beddard's "Animal Coloration" is cited and discussed both by historians of science, and by practising scientists from a number of different fields. For example, the book illuminates the progress of Darwinism, camouflage research, sexual selection, mimicry and the debate on the purpose of animal coloration triggered by Abbott Thayer. These areas are described in turn below.
Darwinism.
The historian Robinson M. Yost explains that Darwinism went into eclipse during the 1890s. At that time, most zoologists felt that natural selection could not be the main cause of biological adaptation, and sought alternative explanations. As a result, many zoologists rejected both Batesian mimicry and Müllerian mimicry. Beddard, writes Yost, explained some problems in the theory of mimicry including that, given how many insect species there are, resemblances between species could arise by chance, and that mimicry was sometimes either useless or actually harmful. In Yost's view, Beddard wanted more evidence that natural selection really was responsible. Yost cites the staunch Darwinist Poulton's hostile review of 1892, which asserts the pre-eminence of Darwin's theory. But, writes Yost, Beddard was not alone in being wary of natural selection.
Camouflage.
The zoologist Martin Stevens and colleagues, in 2006, write that "almost all early discussions of camouflage were of the background-matching type", citing Wallace, Poulton, and Beddard, "until the pioneering work of Thayer (1909) and Cott (1940)", which added disruptive coloration. Cott however both makes use of Beddard as an authority (for the fact that the Hudson's Bay lemming turns white in winter whereas the Scandinavian lemming does not, and for his experiments on the effectiveness of prey coloration on predators) and is critical of him for the "extreme and illogical" opinion held by Beddard and other authors that keeping perfectly still is vital to camouflage. Cott pointed out on that subject that a cryptic colour scheme makes an animal harder to track and to recognize, even while it is moving.
Sexual selection.
The ornithologist Geoffrey Edward Hill, writing in 2002, notes that both Poulton and Beddard discuss sexual selection, and both agreed that "sexual selection by female choice is a likely explanation for the bright coloration of at least some species of birds". In contrast, Hill observes, Cott's detailed 1940 book does not mention it at all; like other zoologists including Wallace and Huxley, Cott preferred explanations "firmly rooted in natural selection".
Mimicry.
The American evolutionary zoologists Jane Van Zandt Brower and Lincoln Pierson Brower followed up the experiments described in the book (pp. 153–159). Beddard, they write, observed the results of feeding the drone fly "Eristalis tenax", a harmless but intimidating Batesian mimic of honeybees, to various predators. A chameleon, a green lizard, and a sand skink eagerly consumed the flies, whereas a thrush and a great spotted woodpecker did not. However, they — like Cott before them, they note — were unable to replicate Beddard's claim that toads would eat insects of any kind, including stinging bees and wasps. They describe their own experimental investigations of bees and their drone fly mimics, like Beddard using toads as the predators, concluding that the Batesian mimicry of the honeybee by the drone fly was "highly effective".
The Thayer debate.
The historian of science Sharon Kingsland, in a 1978 paper on "Abbott Thayer and the protective coloration debate", uses Beddard repeatedly to illuminate the different strands of the argument. She quotes Beddard (p. 94) on how difficult the question of animal coloration seemed in the 1890s. Thayer — an artist, not a scientist — had dived head-first into the debate. One of the protagonists, notes Kingsland, was Joel Asaph Allen, who had reviewed Beddard's book, and who believed that the environment directly influenced animal coloration — Kingsland cites Beddard p. 54 here —, so natural selection seemed to him an unlikely factor, and he pointed out that blending inheritance would dilute the effect of selection. Furthermore, argues Kingsland, again citing Beddard (p. 148), another major protagonist, Alfred Russel Wallace, was emphasizing the problem of conspicuous markings, which could be selected for as warning coloration.
Wallace went so far as to argue, notes Kingsland, that bright colours in sexual dimorphism "resulted from a surplus of vital energy", citing Beddard p. 263 ff. Thayer, on the other hand, had exactly one explanation for everything: natural selection for protective coloration, in particular camouflage by countershading, which radically departed from earlier explanations such as Allen's environmental influences (colours might be affected by light) or Beddard's suggestion that dolphins might have dark backs and light bellies as camouflage when seen from above and from below (Kingsland cites Beddard, p. 115).