Camouflage is the concealment of animals or objects of military interest by any combination of methods that helps them to remain unnoticed. This includes the use of high-contrast disruptive patterns as used on military uniforms, but anything that delays recognition can be used as camouflage. Camouflage involves deception, whether by looking like the background or by resembling something else, which may be plainly visible to observers. [1] [2] This article lists methods used by animals and the military to escape notice.
Different camouflage methods employed by terrestrial, aerial, and aquatic animals, and in military usage, are compared in the table. Several methods are often combined, so for example the Bushbuck is both countershaded over its whole body, and disruptively coloured with small pale spots. Until the discovery of countershading in the 1890s, protective coloration was considered to be mainly a matter of colour matching, [3] but while this is certainly important, a variety of other methods are used to provide effective camouflage. [1] [2]
When an entry is marked Dominant, that method is used widely in that environment, in most cases. For example, countershading is very common among land animals, but not for military camouflage. The dominant camouflage methods on land are countershading and disruptive coloration, supported by less frequent usage of many other methods. [4] The dominant camouflage methods in the open ocean are transparency, [5] reflection, and counterillumination. [6] Transparency and reflectivity are dominant in the top 100 metres (330 ft) of the ocean; counterillumination is dominant from 100 metres (330 ft) down to 1,000 metres (3,300 ft). [6] Most animals of the open sea use one or more of these methods. [6] Military camouflage relies predominantly on disruptive patterns, [7] though methods such as outline disruption are also used, and others have been prototyped.
In 1890 the English zoologist Edward Bagnall Poulton categorised animal colours by their uses, [8] which cover both camouflage and mimicry. [9] Poulton's categories were largely followed by Hugh Cott in 1940. [4] Relevant Poulton categories are listed in the table. Where Poulton's definition covers a method but does not name it explicitly, the category is named in parentheses.
Method | Poulton category [4] [8] | Terrestrial, aerial | Aquatic | Military |
---|---|---|---|---|
Mimesis: resembling something not of interest to the observer | Special aggressive resemblance: mimesis by a predator to avoid scaring off prey | Flower mantis [10] | Green frogfish [11] | Sunshield [12] |
Special protective resemblance: resemblance to a specific object by prey to avoid detection by predators | Dead leaf butterfly [8] | Soft coral spider crab [13] | Observation tree, 1916 [14] | |
Colour matching: having similar colours to the environment, also known as background matching | General protective resemblance: resembling the background in a general way | European tree frog [3] | Brown trout [15] | Khaki uniforms, 1910 [16] |
Disruptive coloration: having high contrast coloration that breaks up outlines, so observers fail to recognise the object | General protective resemblance (a type of) | Papuan frogmouth [17] Dominant | Commerson's frogfish [18] | Disruptive Pattern Material [19] Dominant |
Disruptive eye mask: a disruptive pattern that covers or runs up to the eyes, concealing them | Coincident disruptive pattern (a type of) (Cott) | Common frog [20] | Jack-knifefish [21] | Gun barrel of Sherman Firefly [22] |
Seasonal variation: having coloration that varies with season, usually summer to winter | Variable general protective resemblance: having coloration that resembles the background in each season, in a general way | Arctic hare [23] | Walleye [24] | Snow overalls [25] |
Side or Thayer countershading: having graded toning from dark above to light below, so as to cancel out the apparent effect of self-shadowing when viewed from the side | — | Bushbuck (also has white distractive markings) [26] Dominant | Blue shark [27] | Hugh Cott's guns [28] |
Above/below countershading: having different colours or patterns above and below, to camouflage the upperside for observers from above, and the underside for observers from below | — | Gull (white underside to match sky, improves fishing success) [29] | Penguins [30] | Supermarine Spitfire [31] |
Counterillumination: generating light to raise the brightness of an object to match a brighter background, as of a marine animal's underside against the sea surface | — | — | Sparkling enope squid [32] [33] Dominant (100–1000m) | Yehudi lights (prototype) [34] |
Transparency: letting so much light through that the object is hard to see in typical lighting conditions | General protective resemblance (a type of) | Glass frogs [35] | Comb jellies [32] Dominant (0–100m) | 1916 trials [36] |
Reflection (silvering): reflecting enough light, usually from the sides, to make the object show as a (reflected) patch of the environment | General protective resemblance (a type of) | — | Pilchard [32] Dominant (0–100m) | — |
Self-decoration: covering oneself in materials from the environment | Adventitious protection: covering oneself in materials that are not part of the body | Masked hunter bug [37] | Decorator crabs [38] | Ghillie suit [39] |
Concealment of shadow: having features such as flanges or a flattened body to reduce or hide the shadow | — | Flying lizard [40] | Tasselled wobbegong [41] | Camouflage netting [42] |
Irregular outline: having a broken or complex outline (that may help delay recognition by an observer) | Special protective resemblance (types of) | Comma butterfly [43] | Leafy sea dragon [44] | Scrim, branches [45] |
Distraction: having coloration that distracts an observer's attention away from a feature of the object (such as the head or eye) | — | Eyespots of peacock butterfly [46] | Foureye butterflyfish [47] | False bow wave in ship camouflage [48] |
Distractive markings Small conspicuous marks that distract an observer's attention from recognising the object as a whole [49] | — | Snowy owl with distractively marked plumage [50] | — | Snow camouflage using small distractive marks |
Active camouflage: changing the coloration rapidly enough to maintain resemblance to the current background while moving | Variable aggressive resemblance, variable protective resemblance: varying coloration to resemble the background, in predator and prey respectively | Veiled chameleon [51] | Octopuses [52] | Adaptiv [53] (see that article for image) |
Motion camouflage: following a track such that the object remains between a starting point and the target (e.g. prey) at all times, rather than going straight for the target | — | Hoverfly [54] | — | Air-to-air missile [55] Used primarily for efficiency |
Motion dazzle: rapidly moving a bold pattern of contrasting stripes, confusing an observer's visual processing [56] [57] | — | Zebra [57] | — | Proposal only [56] (NB: Marine Dazzle camouflage did not claim this effect) |
Dazzle camouflage: bold patterns of contrasting stripes, deceiving enemy about ship's heading | — | — | — | Ship camouflage, mainly WW1 [58] Dominant 1917–18 |
Ultra-blackness: extremely black surface, matching very dark background | — | Black panther [59] | Deep-sea fish [60] | Night fighters [61] |
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate, as well as making general aiming easier. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and octopuses, are capable of actively changing their skin pattern and colours, whether for camouflage or for signalling. It is possible that some plants use camouflage to evade being eaten by herbivores.
Abbott Handerson Thayer was an American artist, naturalist, and teacher. As a painter of portraits, figures, animals, and landscapes, he enjoyed a certain prominence during his lifetime, and his paintings are represented in major American art collections. He is perhaps best known for his 'angel' paintings, some of which use his children as models.
In ecology, crypsis is the ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle and mimicry. Crypsis can involve visual, olfactory or auditory concealment. When it is visual, the term cryptic coloration, effectively a synonym for animal camouflage, is sometimes used, but many different methods of camouflage are employed by animals or plants.
Military camouflage is the use of camouflage by an armed force to protect personnel and equipment from observation by enemy forces. In practice, this means applying colour and materials to military equipment of all kinds, including vehicles, ships, aircraft, gun positions and battledress, either to conceal it from observation (crypsis), or to make it appear as something else (mimicry). The French slang word camouflage came into common English usage during World War I when the concept of visual deception developed into an essential part of modern military tactics. In that war, long-range artillery and observation from the air combined to expand the field of fire, and camouflage was widely used to decrease the danger of being targeted or enable surprise. As such, military camouflage is a form of military deception in addition to cultural functions such as political identification.
Hugh Bamford Cott was a British zoologist, an authority on both natural and military camouflage, and a scientific illustrator and photographer. Many of his field studies took place in Africa, where he was especially interested in the Nile crocodile, the evolution of pattern and colour in animals. During the Second World War, Cott worked as a camouflage expert for the British Army and helped to influence War Office policy on camouflage. His book Adaptive Coloration in Animals (1940), popular among serving soldiers, was the major textbook on camouflage in zoology of the twentieth century. After the war, he became a Fellow of Selwyn College, Cambridge. As a Fellow of the Zoological Society of London, he undertook expeditions to Africa and the Amazon to collect specimens, mainly reptiles and amphibians.
Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects, both in predators and in prey.
Decorator crabs are crabs of several different species, belonging to the superfamily Majoidea, that use materials from their environment to hide from, or ward off, predators. They decorate themselves by sticking mostly sedentary animals and plants to their bodies as camouflage, or if the attached organisms are noxious, to ward off predators through aposematism.
Animal colouration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. Some animals are brightly coloured, while others are hard to see. In some species, such as the peafowl, the male has strong patterns, conspicuous colours and is iridescent, while the female is far less visible.
Underwater camouflage is the set of methods of achieving crypsis—avoidance of observation—that allows otherwise visible aquatic organisms to remain unnoticed by other organisms such as predators or prey.
Disruptive coloration is a form of camouflage that works by breaking up the outlines of an animal, soldier or military hardware with a strongly contrasting pattern. It is often combined with other methods of crypsis including background colour matching and countershading; special cases are coincident disruptive coloration and the disruptive eye mask seen in some fishes, amphibians, and reptiles. It appears paradoxical as a way of not being seen, since disruption of outlines depends on high contrast, so the patches of colour are themselves conspicuous.
Adaptive Coloration in Animals is a 500-page textbook about camouflage, warning coloration and mimicry by the Cambridge zoologist Hugh Cott, first published during the Second World War in 1940; the book sold widely and made him famous.
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.
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.
Deception in animals is the transmission of misinformation by one animal to another, of the same or different species, in a way that propagates beliefs that are not true. Mimicry and camouflage enable animals to appear to be other than they are. Prey animals may appear as predators, or vice versa; both predators and prey may be hard to see (crypsis), or may be mistaken for other objects (mimesis). In Batesian mimicry, harmless animals may appear to be distasteful or poisonous. In automimicry, animals may have eyespots in less important parts of the body than the head, helping to distract attack and increase the chance of survival.
Animal coloration provided important early evidence for evolution by natural selection, at a time when little direct evidence was available. Three major functions of coloration were discovered in the second half of the 19th century, and subsequently used as evidence of selection: camouflage ; mimicry, both Batesian and Müllerian; and aposematism.
Coincident disruptive coloration or coincident disruptive patterns are patterns of disruptive coloration in animals that go beyond the usual camouflage function of breaking up the continuity of an animal's shape, to join up parts of the body that are separate. This is seen in extreme form in frogs such as Afrixalus fornasini where the camouflage pattern extends across the body, head, and all four limbs, making the animal look quite unlike a frog when at rest with the limbs tucked in.
Distractive markings serve to camouflage animals or military vehicles by drawing the observer's attention away from the object as a whole, such as noticing its outline. This delays recognition. The markings necessarily have high contrast and are thus in themselves conspicuous. The mechanism therefore relies, as does camouflage as a whole, on deceiving the cognition of the observer, not in blending with the background.
Self-decoration camouflage is a method of camouflage in which animals or soldiers select materials, sometimes living, from the environment and attach these to themselves for concealment.
Disruptive eye masks are camouflage markings that conceal the eyes of an animal from its predators or prey. They are used by prey, to avoid being seen by predators, and by predators to help them approach their prey.
Dazzled and Deceived: Mimicry and Camouflage is a 2009 book on camouflage and mimicry, in nature and military usage, by the science writer and journalist Peter Forbes. It covers the history of these topics from the 19th century onwards, describing the discoveries of Henry Walter Bates, Alfred Russel Wallace and Fritz Müller, especially their studies of butterflies in the Amazon. The narrative also covers 20th-century military camouflage, begun by the painter Abbot Thayer who advocated disruptive coloration and countershading and continued in the First World War by the zoologist John Graham Kerr and the marine artist Norman Wilkinson, who developed dazzle camouflage. In the Second World War, the leading expert was Hugh Cott, who advised the British army on camouflage in the Western Desert.
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ignored (help)In 1916, Brush acquired a small Morane-Borel monoplane (also known as a Morane-Saulnier). He experimented with the possibility of making its wings and fuselage transparent, to reduce its visibility.See also the Etrich Taube, a 1910 design whose translucency effectively camouflaged it above 1200 feet (400 metres).Naughton, Russell (1 January 2002). "Igo Etrich (1879 - 1967) and his 'Taube'". Monash University.