Concealing-Coloration in the Animal Kingdom: An Exposition of the Laws of Disguise Through Color and Pattern; Being a Summary of Abbott H. Thayer's Discoveries is a book published ostensibly by Gerald H. Thayer in 1909, and revised in 1918, but in fact a collaboration with and completion of his father Abbott Handerson Thayer's major work.
The book, illustrated artistically by Abbott Thayer, sets out the controversial thesis that all animal coloration has the evolutionary purpose of camouflage. Thayer rejected Charles Darwin's theory of sexual selection, arguing in words and paintings that even such conspicuous animal features as the peacock's tail or the brilliant pink of flamingoes or roseate spoonbills were effective as camouflage in the right light.
The book introduced the concepts of disruptive coloration to break up an object's outlines, of masquerade, as when a butterfly mimics a leaf, and especially of countershading, where an animal's tones make it appear flat by concealing its self-shadowing.
The book was criticised by big game hunter and politician Theodore Roosevelt for its central assertion that every aspect of animal coloration is effective as camouflage. Roosevelt's detailed reply attacked the biased choice of examples to suit Abbott Thayer's thesis and the book's reliance on unsubstantiated claims in place of evidence. The book was more evenly criticised by zoologist and camouflage researcher Hugh Cott, who valued Thayer's work on countershading but regretted his overenthusiastic attempts to explain all animal coloration as camouflage. Thayer was mocked to a greater or lesser extent by other scientific reviewers.
Overview
Abbott Thayer (1849–1921) was an American artist, known for his figure paintings, often of "virginal, spiritual beauty", which were sometimes, as in his most famous painting, Angel, modeled on his children.Meryman, 1999. He had studied at an art school in Paris, but unlike James McNeill Whistler he returned to the United States. Along with seeking timeless beauty, Thayer also became obsessed with nature, which he felt contained the pure beauty that he was seeking to capture in his paintings.
Thayer's close observation led him to notice what scientists such as Edward Bagnall Poulton were just beginning to describe.Poulton, 1890. This was that many animals were "painted" the opposite way to how painters create the appearance of solidity in figures. A canvas is flat, and areas of uniform color painted on a canvas also appear flat. To make a body appear to have depth and solidity, the artist paints in shadows on the body itself. The top of an animal's back, facing the sky, remains bright, while it must become darker towards its underside. Thayer was excited to realize that by reversing such shading, nature could and did make animals appear flat. He was so passionate about this "concealing coloration" theory that he called it his "second child". Poulton had noticed countershading in certain caterpillars, but he had not realized that the phenomenon was widespread, and he championed Thayer's theory in a 1902 article in Nature.Forbes, 2009. p. 74.
However, Thayer was not a scientist, and he lacked a scientist's inclination to attempt to test and disprove every aspect of a new theory. Instead, Thayer came to believe that the theory belonged to artists, with their trained perception: "The whole basis of picture making consists in contrasting against its background every object in the picture", he argued.
The obsession led him to deny that animals could be colored for other reasons: for protection by mimicry, as the naturalist Henry Walter Bates had proposed, supported by many examples of butterflies from South America; through sexual selection, as Charles Darwin had argued, again supported by many observations. The unbalanced treatment of animal coloration in Concealing-Coloration in the Animal Kingdom encapsulates Thayer's partial understanding and his rejection of other theories.Forbes, 2009. pp. 73-84.
The same obsession led him, later, to attempt to persuade the military to adopt camouflage based on his ideas, traveling to London in 1915, and writing "passionate letters" to the Assistant Secretary to the US Navy, Franklin Delano Roosevelt, in 1917.
Approach
Text
Gerald Thayer describes the book as having two main purposes: to present Abbott Thayer's research to naturalists; and to make the subject available to a wider readership.Thayer, 1909. p viii.
The book's list of contents reveals Thayer's heavy reliance on bird examples, filling 16 of the 27 chapters. Other vertebrates occupy 5 chapters. Insects receive 3 chapters, of which two are dedicated to lepidoptera - one to caterpillars, one to adult butterflies and moths; the remaining one devotes 14 pages to all other insects, starting with orthoptera including the leaf-mimic grasshoppers.
Illustrations
The book has 16 colored plates of paintings by Abbott Thayer and Richard S. Meryman, including the well known frontispiece "Peacock amid foliage", and the heavily criticised images of wood ducks, blue jays against snow, roseate spoonbills and flamingoes "at dawn or sunset, and the skies they picture". The last 4 colored plates are of caterpillars. Gerald Thayer claims that "The illustrations are of particular importance, inasmuch as they include what we believe to be the first scientific paintings ever published of animals lighted as they actually are in nature".
There are 140 black and white figures, mainly photographs with a few diagrams and drawings. Half the photographs are of birds. The photographs are from various sources, "gleaned from periodicals, or secured by special advertising."Thayer, 1909. p ix.
Contents
Introduction by Abbott H. Thayer. An essay on the psychological and other basic principles of the subject. Outline of the book's scope. "The Law which underlies Protective Coloration" Definition of terms. Obliterative Shading First principles of the use of markings with obliterative shading Picture-patterns, with obliterative shading, on birds. American Woodcock, and Snipe Picture-patterns on obliteratively-shaded birds, continued. Terrestrial Goatsuckers Picture-patterns on counter-shaded birds. Forest Grouse, Owls, European Woodcock Picture-patterns on counter-shaded birds, continued. Grass-patterns, heather-patterns Picture-patterns on counter-shaded birds, continued. Scansorial (climbing) birds Picture-patterns on counter-shaded birds, continued. Shore-birds Picture-patterns on counter-shaded birds, continued. Reed-patterns, etc., of Bitterns Background-picturing on counter-shaded birds, continued. Marsh-birds. Wood Duck Background-picturing on counter-shaded birds, continued. Birds of the ocean Birds, etc. The inherent 'obliterative' power of markings. 'Ruptive' and 'Secant' patterns Birds, etc. Special functions of markings Birds. Masking of bill and feet for offensive purposes Birds, etc. The manifold obliterative power of iridescence Birds, etc. Appendages, and their part in 'obliteration' Birds: miscellany. "Mimicry" (vs 'obliteration') Birds, concluded Mammals Mammals, continued Mammals, concluded Fishes Reptiles and Amphibians Caterpillars A glance at Insects other than Lepidoptera Butterflies and Moths
Outline
Chapter 1 sets out the "long-ignored laws" of "protective coloration", an act which "has waited for an artist" to perceive. Thayer explains the principle of countershading with a diagram, arguing that a naive view of being "colored like their surroundings" does not explain how animal camouflage works. He acknowledges the prior work of Edward Bagnall Poulton (The Colours of Animals, 1890) in identifying countershading in caterpillars, quoting some passages where Poulton describes how larvae and pupae can appear flat. Countershading is named as "the law which underlies protective coloration", rather than as one of several principles.
Chapter 2 defines the book's terms, equating "mimicry" with "protective resemblance", so that it becomes a form of "protective or disguising coloration". Thayer distinguishes "concealing-colors" (mainly countershading for "invisibility") from the "other" branch of protective coloration, which includes most kinds of mimicry, for "deceptive visibility". The two branches are then named "obliterative coloration" and "mimicry". Mimicry is dismissed as playing "a very insignificant part" in the "higher orders", i.e. it is limited mainly to invertebrates. A fine photograph of a "white fowl, lacking counter-shading, against a flat white cloth" demonstrates that camouflage is more than color matching. Thayer then gives several examples of what he considers countershaded animals.
Chapter 3 describes the combination of markings with countershading, with photographs of a model bird and of a woodcock, showing how in the correct position these are well camouflaged with "wonderful obliterative picture-patterns", but wrongly positioned or upside down (with a photograph of a dead woodcock) they are easily visible.
Chapters 4 and 5 illustrate more "picture-patterns" in well camouflaged birds including Wilson's snipe and whip-poor-will (nighthawks and goatsuckers, Caprimulgidae). Thayer describes these as showing "obliteration, or merging with the background" but that their patterning is close to mimicry as they "perfectly" resemble objects such as "a stone or mossy log".
Chapter 6 argues that some birds such as the ruffed grouse have patterns designed as camouflage against distant backgrounds, with a painting of a bird against a forest background as evidence. "The bird is in plain sight, but invisible". For the great horned owl, a piece of the wing is "super-imposed" on a photograph of a wood, "to show how closely the owl's patterns reproduce such a forest interior." The text describes the owl as having "a highly developed forest-vista pattern". Chapter 7 similarly argues for grass and heather patterns on "terrestrial" (as opposed to arboreal) birds. The disruptively patterned white-tailed ptarmigan is shown in "a very remarkable photograph" by Evan Lewis. Thayer attempts to classify the camouflage types, for example writing
Chapter 8 continues the theme with "scansorial" or tree climbing birds. Chapter 9 claims that "obliterative shading, pure and simple, is the rule among the Shore Birds" such as sandpipers and curlew. Chapter 10 describes the "background-picturing" of bitterns, birds which live in reedbeds, where
Chapter 11 argues (in a way that was heavily criticised when the book appeared, see below) that water birds, some of them highly conspicuous like the jacana and notoriously the male wood duck, are colored for camouflage: "The beautifully contrasted black-and-white bars on the flanks of the Wood Duck (Aix sponsa) are ripple pictures, and as potent [as camouflage], in their place, as the most elaborate markings of land birds".Thayer, 1909. p 62. Chapter 12 argues that the "pure white" of ocean birds such as gulls and terns equally functions as camouflage. Thayer admits that these often appear conspicuous, but argues that against varied backgrounds, white offers "the greatest average inconspicuousness against the ocean" (his italics) or against the bright sky when seen from below.
Chapter 13 analyses "markings and patterns in detail, starting with a color plate that shows the effect of disruptive patterning, which Thayer calls "strong 'secant' and 'ruptive' patterns". Using a photograph of an oystercatcher at its nest by Cherry and Richard Kearton, Thayer argues that the boldly marked bird (mainly black above, white below, with red beak) is both countershaded and "ruptively" patterned. Chapter 14 discusses the barred markings of hawks and owls, with further fine plates of photographs by the Keartons of disruptively patterned waders and their cryptic chicks. The ringed plover is described as having "eye-masking and 'obliterative' shadow-and-hole-picturing pattern".