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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 The leopard (''Panthera pardus'') is one of the five extant in the ', a member of the cat , . It occurs in a wide range in , in some parts of and , , and on the to and . It is listed as on the because leopard populations are threatened ...

leopard
's spotted coat, the
battledress A combat uniform, field uniform, battledress or military fatigues, is a casual type of uniform used by military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfar ...
of a modern
soldier A soldier is a person who is a member of a professional army An army (from Latin ''arma'' "arms, weapons" via Old French ''armée'', "armed" eminine, ground force or land force is a fighting force that fights primarily on land. In the ...

soldier
, and the
leaf-mimic katydid There are many insects in the family Tettigoniidae (bush crickets or katydids) which are mimicry, mimics of leaves. Amongst others, these include the "Pterochrozini" - previously a tribe, but now placed in its own subfamily Pterochrozinae. Gallery ...
's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast
disruptive coloration Disruption, disruptive, or disrupted may refer to: Business *Creative disruption Creative disruption (disruption concept in a creative context) was introduced in 1992 by TBWA's chairman Jean-Marie Dru. It refers to a radical change in a marketpl ...
, eliminating shadow, and
countershading Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects ...

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 Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds in both brightness and wavelength. Marine animals o ...
on the undersides of
cephalopod A cephalopod is any member of the mollusca Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks (). Around 85,000 extant taxon, extant species of molluscs are ...
s such as
squid Squid are cephalopod A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are cha ...

squid
. Some animals, such as
chameleon Chameleons or chamaeleons (Family (biology), family Chamaeleonidae) are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015. These species come in a range of colors, and many species have th ...

chameleon
s and
octopus An octopus (pl. octopuses/octopi, see below for variants) is a soft-bodied, eight- limbed mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks (). Ar ...

octopus
es, 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
herbivore 250px, Tracks made by terrestrial gastropods with their radulas, scraping green algae from a surface inside a greenhouse">alga.html" ;"title="radulas, scraping green alga">radulas, scraping green algae from a surface inside a greenhouse A her ...
s.
Military camouflage Military camouflage is the use of camouflage 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. Exa ...
was spurred by the increasing range and accuracy of firearms in the 19th century. In particular the replacement of the inaccurate
musket s aboard the frigate A frigate () is a type of warship, having various sizes and roles over time. In the 17th century, a frigate was any warship built for speed and maneuverability, the description often used being "frigate-built". These co ...
with the
rifle A rifle is a long-barrelled firearm A firearm is any type of gun A gun is a ranged weapon designed to use a shooting tube ( gun barrel) to launch typically solid projectiles, but can also project pressurized liquid (e.g. water gun ...

rifle
made personal concealment in battle a survival skill. In the 20th century, military camouflage developed rapidly, especially during the
First World War World War I, often abbreviated as WWI or WW1, also known as the First World War or the Great War, was a that began on 28 July 1914 and ended on 11 November 1918. It involved much of , as well as , the and , and was also fought ...
. On land, artists such as
André Mare Charles André Mare (1885–1932), or André-Charles Mare, was a French painter and textile designer, and co-founder of the Company of French Art (''la Compagnie des Arts Français'') in 1919. He was a designer of colorful textiles, and was one of ...
designed camouflage schemes and observation posts disguised as trees. At sea, merchant ships and troop carriers were painted in
dazzle Dazzle may refer to: * Glare (vision), difficulty seeing in the presence of bright light * Dazzle (fabric), a type of polyester fabric * Dazzle (manga), ''Dazzle'' (manga), a Japanese manga series by Minari Endoh * Dazzle (song), "Dazzle" (song), a ...
patterns that were highly visible, but designed to confuse enemy submarines as to the target's speed, range, and heading. During and after the
Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a that lasted from 1939 to 1945. It involved —including all of the great powers—forming two opposing s: the and the . In a total war directly involving m ...
, a variety of camouflage schemes were used for
aircraft An aircraft is a vehicle or machine that is able to fly Flies are insect Insects or Insecta (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Lat ...
and for ground vehicles in different theatres of war. The use of radar since the mid-20th century has largely made camouflage for fixed-wing military aircraft obsolete. Non-military use of camouflage includes making cell telephone towers less obtrusive and helping hunters to approach wary game animals. Patterns derived from military camouflage are frequently used in fashion clothing, exploiting their strong designs and sometimes their symbolism. Camouflage themes recur in modern art, and both figuratively and literally in science fiction and works of literature.


History

In ancient Greece,
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...

Aristotle
(384–322 BC) commented on the colour-changing abilities, both for camouflage and for
signalling In signal processing Signal processing is an electrical engineering subfield that focuses on analysing, modifying, and synthesizing signals such as audio signal processing, sound, image processing, images, and scientific measurements. Sig ...
, of
cephalopod A cephalopod is any member of the mollusca Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks (). Around 85,000 extant taxon, extant species of molluscs are ...
s including the octopus, in his ''
Historia animalium ''History of Animals'' ( grc-gre, Τῶν περὶ τὰ ζῷα ἱστοριῶν, ''Ton peri ta zoia historion'', "Inquiries on Animals"; la, Historia Animalium, "History of Animals") is one of the major texts on biology by the ancient Gree ...
'':Aristotle (c. 350 BC). ''Historia Animalium''. IX, 622a: 2–10. Cited in Borrelli, Luciana; Gherardi, Francesca; Fiorito, Graziano (2006). ''A catalogue of body patterning in Cephalopoda''. Firenze University Press.
Abstract
/ref> Camouflage has been a topic of interest and research in
zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical stru ...
for well over a century. According to
Charles Darwin Charles Robert Darwin (; ; 12 February 1809 – 19 April 1882) was an English , and , best known for his contributions to the science of . His proposition that all species of life have descended from is now widely accepted and cons ...

Charles Darwin
's 1859 theory of
natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype right , Here the relation between genotype and phenotype is illustrated, using a Punnett square, for the character of peta ...
, features such as camouflage
evolved Evolution is change in the heritable Heredity, also called inheritance or biological inheritance, is the passing on of Phenotypic trait, traits from parents to their offspring; either through asexual reproduction or sexual reproduction, ...

evolved
by providing individual animals with a reproductive advantage, enabling them to leave more offspring, on average, than other members of the same
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...

species
. In his ''
Origin of Species ''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''),The book's full original title was ''On the Origin of Species by Mea ...

Origin of Species
'', Darwin wrote: The English zoologist
Edward Bagnall Poulton Sir Edward Bagnall Poulton, Fellow of the Royal Society, FRS FRSE, HFRSE Linnean Society of London, FLS (27 January 1856 – 20 November 1943) was a British evolutionary biologist who was a lifelong advocate of natural selection through a perio ...
studied
animal coloration upBright coloration of orange elephant ear sponge, '' Agelas clathrodes'' signals its bitter taste to predators Animal coloration is the general appearance of an animal resulting from the reflection or emission of light Light or visible ...
, especially camouflage. In his 1890 book ''
The Colours of Animals ''The Colours of Animals'' is a zoology Zoology ()The pronunciation of zoology as is typically regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the anatomy, structure, e ...
'', he classified different types such as "special protective resemblance" (where an animal looks like another object), or "general aggressive resemblance" (where a predator blends in with the background, enabling it to approach prey). His experiments showed that swallow-tailed moth
pupae '' A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. The pupal stage is found only in Holometabolism, holometabolous insects, those that undergo a complet ...
were camouflaged to match the backgrounds on which they were reared as
larvae A larva (plural larvae ) is a distinct juvenile form many animal Animals (also called Metazoa) are organisms that form the Animalia. With few exceptions, animals , , are , can , and grow from a hollow sphere of , the , during . Ove ...

larvae
. Poulton's "general protective resemblance" was at that time considered to be the main method of camouflage, as when Frank Evers Beddard wrote in 1892 that "tree-frequenting animals are often green in colour. Among vertebrates numerous species of
parrot Parrots, also known as psittacines , are bird Birds are a group of warm-blooded vertebrates constituting the class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class ...

parrot
s,
iguana ''Iguana'' (, ) is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

iguana
s, , and the are examples". Beddard did however briefly mention other methods, including the "alluring coloration" of the
flower mantis Flower mantises are praying mantis species that display behaviors of mimicry In evolutionary biology Evolutionary biology is the subfield of biology that studies the evolution, evolutionary processes (natural selection, common descent, ...
and the possibility of a different mechanism in the . He wrote that "the scattered green spots upon the under surface of the wings might have been intended for a rough sketch of the small flowerets of the plant n_umbellifer.html" ;"title="umbellifer.html" ;"title="n umbellifer">n umbellifer">umbellifer.html" ;"title="n umbellifer">n umbellifer so close is their mutual resemblance." He also explained the coloration of sea fish such as the mackerel: "Among pelagic fish it is common to find the upper surface dark-coloured and the lower surface white, so that the animal is inconspicuous when seen either from above or below." The artist
Abbott Handerson Thayer Abbott Handerson Thayer (August 12, 1849May 29, 1921) was an American artist, naturalist and teacher. As a Painting, painter of portraits, figures, animals and Landscape art, landscapes, he enjoyed a certain prominence during his lifetime, and his ...
formulated what is sometimes called Thayer's Law, the principle of
countershading Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects ...

countershading
. However, he overstated the case in the 1909 book ''
Concealing-Coloration in the Animal Kingdom ''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, ...
'', arguing that "All patterns and colors whatsoever of all animals that ever preyed or are preyed on are under certain normal circumstances obliterative" (that is, cryptic camouflage), and that "Not one '
mimicry In evolutionary biology Evolutionary biology is the subfield of biology that studies the evolution, evolutionary processes (natural selection, common descent, speciation) that produced the Biodiversity, diversity of life on Earth. In the 1 ...

mimicry
' mark, not one ' warning color'... nor any ' sexually selected' color, exists anywhere in the world where there is not every reason to believe it the very best conceivable device for the concealment of its wearer", and using paintings such as ''Peacock in the Woods'' (1907) to reinforce his argument. Thayer was roundly mocked for these views by critics including
Teddy Roosevelt Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or his initials T. R., was an American statesman, conservationist, naturalist, historian, and writer, who served as the 26th president of the Unite ...

Teddy Roosevelt
. The English zoologist
Hugh Cott Hugh Bamford Cott (6 July 1900 – 18 April 1987) 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 Africa is the ...
's 1940 book ''
Adaptive Coloration in Animals ''Adaptive Coloration in Animals'' is a 500-page textbook about camouflage, warning coloration and mimicry by the Cambridge Cambridge ( ) is a College town, university city and the county town of Cambridgeshire, England, on the River Cam a ...
'' corrected Thayer's errors, sometimes sharply: "Thus we find Thayer straining the theory to a fantastic extreme in an endeavour to make it cover almost every type of coloration in the animal kingdom." Cott built on Thayer's discoveries, developing a comprehensive view of camouflage based on "maximum disruptive contrast", countershading and hundreds of examples. The book explained how
disruptive camouflage Disruption, disruptive, or disrupted may refer to: Business *Creative disruption Creative disruption (disruption concept in a creative context) was introduced in 1992 by TBWA's chairman Jean-Marie Dru. It refers to a radical change in a marketpl ...
worked, using streaks of boldly contrasting colour, paradoxically making objects less visible by breaking up their outlines. While Cott was more systematic and balanced in his view than Thayer, and did include some experimental evidence on the effectiveness of camouflage, his 500-page textbook was, like Thayer's, mainly a
natural history Natural history is a domain of inquiry involving organisms, including animals, fungus, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history ...

natural history
narrative which illustrated theories with examples. Experimental evidence that camouflage helps prey avoid being detected by
predator Predation is a biological interaction In ecology Ecology (from el, οἶκος, "house" and el, -λογία, label=none, "study of") is the study of the relationships between living organisms, including humans, and their physical env ...

predator
s was first provided in 2016, when ground-nesting birds (
plovers Plovers ( or ) are a widely distributed group of wader, wading birds belonging to the subfamily Charadriinae. Description There are about 66 species in the subfamily, most of them called "plover" or "Dotterel (disambiguation), dotterel". Th ...
and coursers) were shown to survive according to how well their egg contrast matched the local environment.


Fossil history

Camouflage is a soft-tissue feature that is rarely preserved in the
fossil A fossil (from Classical Latin Classical Latin is the form of Latin language Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication used by humans, inc ...

fossil
record, but rare fossilised skin samples from the
Cretaceous The Cretaceous ( ) is a geological period A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place. These periods form elements of a hierarchy of division ...

Cretaceous
period show that some marine reptiles were countershaded. The skins, pigmented with dark-coloured
eumelanin Melanin (; from el, μέλας ''melas'', "black, dark") is a broad term for a group of natural pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at ...
, reveal that both leatherback turtles and
mosasaur Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Ancient Greek, Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Ma ...
s had dark backs and light bellies. There is fossil evidence of camouflaged insects going back over 100 million years, for example lacewings larvae that stick debris all over their bodies much as their modern descendants do, hiding them from their prey. Dinosaurs appear to have been camouflaged, as a 120 million year old fossil of a ''
Psittacosaurus ''Psittacosaurus'' ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 126 and 101 million years ago. It is notable for being the most species-rich non-avian dinosaur gen ...

Psittacosaurus
'' has been preserved with
countershading Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects ...

countershading
.


Principles

Camouflage can be achieved by different methods, described below. Most of the methods help to hide against a background; but mimesis and motion dazzle protect without hiding. Methods may be applied on their own or in combination. Many mechanisms are visual, but some research has explored the use of techniques against
olfactory Olfaction, or the sense of smell, is the special sense through which smells (or odors) are perceived. It occurs when an odor binds to a olfactory receptor, receptor within the nasal cavity, transmitting a signal through the olfactory system. Ol ...
(scent) and
acoustic Acoustic may refer to: Music Albums * Acoustic (Bayside EP), ''Acoustic'' (Bayside EP) * Acoustic (Britt Nicole EP), ''Acoustic'' (Britt Nicole EP) * Acoustic (Joey Cape and Tony Sly album), ''Acoustic'' (Joey Cape and Tony Sly album), 2004 * Aco ...

acoustic
(sound) detection. Methods may also apply to military equipment.


Resemblance to surroundings

Some animals' colours and patterns resemble a particular natural background. This is an important component of camouflage in all environments. For instance, tree-dwelling
parakeet A parakeet is any one of many small to medium-sized species of parrot, in multiple Genus, genera, that generally has long tail feathers. Older spellings still sometimes encountered are paroquet or paraquet. In American English, the word parakee ...
s are mainly green;
woodcock The woodcocks are a group of seven or eight very similar living species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species i ...

woodcock
s of the forest floor are brown and speckled; reedbed
bittern Bitterns are birds belonging to the subfamily Botaurinae of the heron family Ardeidae The herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 64 recognised species, some of which are referred to as ...

bittern
s are streaked brown and buff; in each case the animal's coloration matches the hues of its habitat. Similarly,
desert animals A xerocole (), is a general term referring to any animal that is adapted to live in a desert. The main challenges xerocoles must overcome are lack of water and excessive heat. To conserve water they avoid evaporation and concentrate excretions (i.e ...
are almost all desert coloured in tones of sand, buff, ochre, and brownish grey, whether they are mammals like the
gerbil The Mongolian gerbil or Mongolian jird (''Meriones unguiculatus'') is a small rodent belonging to the subfamily Gerbillinae. Their body size is typically 110–135mm (4½" to 5¼"), with a 95–120mm (3¾" to 4¾") tail, and body weight 60–1 ...

gerbil
or
fennec fox The fennec fox (''Vulpes zerda'') is a small crepuscular An adult firefly (''Photuris lucicrescens'') or "lightning bug" – a crepuscular beetle A crepuscular animal is one that is active primarily during the twilight period. This is ...

fennec fox
, birds such as the
desert lark The desert lark (''Ammomanes deserti'') breeds in deserts and semi-deserts from Morocco to western India. It has a very wide distribution and faces no obvious threats, and surveys have shown that it is slowly increasing in numbers as it expands ...
or
sandgrouse Sandgrouse is the common name for Pteroclidae , a family (biology), family of sixteen species of bird, members of the order Pterocliformes . They are traditionally placed in two Genus, genera. The two central Asian species are classified as ''Syr ...

sandgrouse
, or reptiles like the
skink Skinks are lizard Lizards (suborder Lacertilia) are a widespread group of Squamata, squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyleti ...

skink
or horned viper. Military uniforms, too, generally resemble their backgrounds; for example
khaki The color khaki (, ) is a light shade of brown with a yellowish tinge. Khaki has been used by many armies around the world for uniforms, including camouflage Camouflage is the use of any combination of materials, coloration, or illuminat ...

khaki
uniforms are a muddy or dusty colour, originally chosen for service in South Asia. Many moths show
industrial melanism Industrial melanism is an evolution Evolution is change in the Heredity, heritable Phenotypic trait, characteristics of biological populations over successive generations. These characteristics are the Gene expression, expressions of genes ...
, including the
peppered moth The peppered moth (''Biston betularia'') is a temperate species of night-flying moth Moths are a paraphyletic group of insects that includes all members of the Order (biology), order Lepidoptera that are not Butterfly, butterflies, with mot ...

peppered moth
which has coloration that blends in with tree bark. The coloration of these insects evolved between 1860 and 1940 to match the changing colour of the tree trunks on which they rest, from pale and mottled to almost black in polluted areas. This is taken by zoologists as evidence that camouflage is influenced by natural selection, as well as demonstrating that it changes where necessary to resemble the local background. File:Tanzania 0607 cropped Nevit.jpg, Black-faced sandgrouse is coloured like its desert background. File:Caprimulgus aegyptius.jpg, Egyptian nightjar nests in open sand with only its camouflaged plumage to protect it. File:Podargus papuensis - Daintree River.jpg,
Papuan frogmouth The Papuan frogmouth (''Podargus papuensis'') is a species of bird in the family Podargidae. Taxonomy The species was originally described by zoologist Jean René Constant Quoy and naturalist Joseph Paul Gaimard in 1830. The three subspecies a ...
resembles a broken branch. File:Katydid camouflaged in basil plant.jpg, Bright green
katydid Insects in the family (biology), family Tettigoniidae are commonly called katydids (in Australia, South Africa, Canada, and the United States), or bush crickets. They have previously been known as "long-horned grasshoppers". More than 6,400 spe ...

katydid
has the colour of fresh vegetation.


Disruptive coloration

Disruptive patterns use strongly contrasting, non-repeating markings such as spots or stripes to break up the outlines of an animal or military vehicle, or to conceal telltale features, especially by masking the eyes, as in the . Disruptive patterns may use more than one method to defeat visual systems such as
edge detection Edge detection includes a variety of mathematical methods that aim at identifying points in a digital image at which the image brightness changes sharply or, more formally, has discontinuities. The points at which image brightness changes sharpl ...

edge detection
. Predators like the
leopard The leopard (''Panthera pardus'') is one of the five extant in the ', a member of the cat , . It occurs in a wide range in , in some parts of and , , and on the to and . It is listed as on the because leopard populations are threatened ...

leopard
use disruptive camouflage to help them approach prey, while potential prey use it to avoid detection by predators. Disruptive patterning is common in military usage, both for uniforms and for military vehicles. Disruptive patterning, however, does not always achieve crypsis on its own, as an animal or a military target may be given away by factors like shape, shine, and shadow. The presence of bold skin markings does not in itself prove that an animal relies on camouflage, as that depends on its behaviour. Roosevelt attacks Thayer on page 191, arguing that neither zebra nor giraffe are "'adequately obliterated' by countershading or coloration pattern or anything else." For example, although
giraffe The giraffe is a tall African mammal Mammals (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''c ...

giraffe
s have a high contrast pattern that could be disruptive coloration, the adults are very conspicuous when in the open. Some authors have argued that adult giraffes are cryptic, since when standing among trees and bushes they are hard to see at even a few metres distance. However, adult giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves, even from lions, rather than on camouflage. A different explanation is implied by young giraffes being far more vulnerable to predation than adults. More than half of all giraffe calves die within a year, and giraffe mothers hide their newly born calves, which spend much of the time lying down in cover while their mothers are away feeding. The mothers return once a day to feed their calves with milk. Since the presence of a mother nearby does not affect survival, it is argued that these juvenile giraffes must be very well camouflaged; this is supported by coat markings being strongly . The possibility of camouflage in plants has been little studied until the late 20th century. Leaf
variegation '' 'Panascè', a bicolor (yellow-green) common fig cultivar. This Italian cultivar is a '' chimera''. Variegation is the appearance of differently coloured zones in the leaves and sometimes the Plant stem, stems and fruit of plants. Species wi ...
with white spots may serve as camouflage in forest
understory In forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and na ...
plants, where there is a dappled background; leaf mottling is correlated with closed habitats. Disruptive camouflage would have a clear evolutionary advantage in plants: they would tend to escape from being eaten by
herbivore 250px, Tracks made by terrestrial gastropods with their radulas, scraping green algae from a surface inside a greenhouse">alga.html" ;"title="radulas, scraping green alga">radulas, scraping green algae from a surface inside a greenhouse A her ...
s. Another possibility is that some plants have leaves differently coloured on upper and lower surfaces or on parts such as veins and stalks to make green-camouflaged insects conspicuous, and thus benefit the plants by favouring the removal of herbivores by carnivores. These hypotheses are testable. File:Great male Leopard in South Afrika-JD.JPG, Leopard: a disruptively camouflaged predator File:T-90 main battle tank (2).jpg, Russian T-90 battle tank painted in bold disruptive pattern of sand and green File:Gaboon viper (4530693343).jpg,
Gaboon viper The Gaboon viper (''Bitis gabonica'') is a viper The Viperidae (vipers) are a family of venomous snakes found in most parts of the world, with the exception of Antarctica Antarctica ( or ) is Earth's southernmost continent. It contains th ...

Gaboon viper
's bold markings are powerfully disruptive. File:Ptarmigan_and_five_chicks.JPG, A ptarmigan and five chicks exhibit exceptional disruptive camouflage File:Jumping spider with prey.jpg,
Jumping spider Jumping spiders or the Salticidae are a family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or soci ...

Jumping spider
: a disruptively camouflaged invertebrate predator File:Saw Greenbriar - Smilax bona-nox, Colt Creek State Park, Lakeland, Florida.jpg, Many
understory In forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and na ...
plants such as the saw greenbriar, '''' have pale markings, possibly disruptive camouflage.


Eliminating shadow

Some animals, such as the
horned lizard Horned lizards (''Phrynosoma''), also known as horny toads or horntoads, are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific s ...

horned lizard
s of North America, have evolved elaborate measures to eliminate
shadow A shadow is a dark area where light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception, perceived by the human eye. Visible light is usually defined as havi ...

shadow
. Their bodies are flattened, with the sides thinning to an edge; the animals habitually press their bodies to the ground; and their sides are fringed with white scales which effectively hide and disrupt any remaining areas of shadow there may be under the edge of the body. The theory that the body shape of the horned lizards which live in open desert is adapted to minimise shadow is supported by the one species which lacks fringe scales, the roundtail horned lizard, which lives in rocky areas and resembles a rock. When this species is threatened, it makes itself look as much like a rock as possible by curving its back, emphasizing its three-dimensional shape. Some species of butterflies, such as the speckled wood, '''', minimise their shadows when perched by closing the wings over their backs, aligning their bodies with the sun, and tilting to one side towards the sun, so that the shadow becomes a thin inconspicuous line rather than a broad patch. Similarly, some ground-nesting birds, including the European nightjar, select a resting position facing the sun. Eliminating shadow was identified as a principle of military camouflage during the Second world war, Second World War. File:Ibexes.jpg, Three countershaded and cryptically coloured ibex almost invisible in the Israeli desert File:Armoured personnel carriers, Eriboll - geograph.org.uk - 1316295.jpg, "Shape, shine, shadow" make these 'camouflaged' military vehicles easily visible. File:Phrynosoma mcallii.jpg, The flat-tail horned lizard's body is flattened and fringed to minimise its shadow. File:Øvelse på Evjemoen Tropp 4.2 - camouflage nettings.jpg, Camouflage Net (textile), netting is draped away from a military vehicle to reduce its shadow. File:Perfect Camouflage (Caterpillar on teakwood branch).jpg, A caterpillar's fringe of bristles conceals its shadow.


Distraction

Many prey animals have conspicuous high-contrast markings which paradoxically attract the predator's gaze. These distractive markings may serve as camouflage by distracting the predator's attention from recognising the prey as a whole, for example by keeping the predator from identifying the prey's outline. Experimentally, search times for blue tits increased when artificial prey had distractive markings.


Self-decoration

Some animals actively seek to hide by decorating themselves with materials such as twigs, sand, or pieces of shell from their environment, to break up their outlines, to conceal the features of their bodies, and to match their backgrounds. For example, a caddisfly larva builds a decorated case and lives almost entirely inside it; a Naxia tumida, decorator crab covers its back with seaweed, sponges, and stones. The Nymph (biology), nymph of the predatory Reduvius personatus, masked bug uses its hind legs and a 'Tarsus (skeleton), tarsal fan' to decorate its body with sand or dust. There are two layers of bristles (trichomes) over the body. On these, the nymph spreads an inner layer of fine particles and an outer layer of coarser particles. The camouflage may conceal the bug from both predators and prey. Similar principles can be applied for military purposes, for instance when a sniper wears a ghillie suit designed to be further camouflaged by decoration with materials such as tufts of grass from the sniper's immediate environment. Such suits were used as early as 1916, the British army having adopted "coats of motley hue and stripes of paint" for snipers. Cott takes the example of the larva of the blotched emerald moth, which fixes a screen of fragments of leaves to its specially hooked bristles, to argue that military camouflage uses the same method, pointing out that the "device is ... essentially the same as one widely practised during the Great War for the concealment, not of caterpillars, but of caterpillar-tractors, [gun] battery positions, observation posts and so forth." File:Hyastenus elatus.jpg, This Hyastenus elatus, decorator crab has covered its body with sponges. File:IDF-CombatEngineeringSniper001.jpg, Sniper in a Ghillie suit with plant materials File:Camouflaged crab.JPG, Crab camouflaged with algae File:Reduvius personatus, Masked Hunter Bug nymph camouflaged with sand grains.JPG, ''Reduvius personatus'', masked hunter bug nymph, camouflaged with sand grains File:Battle of Lake Khasan-Camouflaged soviet tanks.jpg, Soviet tanks under netting dressed with vegetation, 1938


Cryptic behaviour

Movement catches the eye of prey animals on the lookout for predators, and of predators hunting for prey. Most methods of crypsis therefore also require suitable cryptic behaviour, such as lying down and keeping still to avoid being detected, or in the case of stalking predators such as the tiger, moving with extreme stealth, both slowly and quietly, watching its prey for any sign they are aware of its presence. As an example of the combination of behaviours and other methods of crypsis involved, young giraffes seek cover, lie down, and keep still, often for hours until their mothers return; their skin pattern blends with the pattern of the vegetation, while the chosen cover and lying position together hide the animals' shadows. The flat-tail horned lizard similarly relies on a combination of methods: it is adapted to lie flat in the open desert, relying on stillness, its cryptic coloration, and concealment of its shadow to avoid being noticed by predators. In the ocean, the leafy sea dragon sways mimetically, like the seaweeds amongst which it rests, as if rippled by wind or water currents. Swaying is seen also in some insects, like Macleay's spectre stick insect, ''Extatosoma tiaratum''. The behaviour may be motion crypsis, preventing detection, or motion masquerade, promoting misclassification (as something other than prey), or a combination of the two.


Motion camouflage

Most forms of camouflage are ineffective when the camouflaged animal or object moves, because the motion is easily seen by the observing predator, prey or enemy. However, insects such as Hoverfly, hoverflies and Dragonfly, dragonflies use motion camouflage: the hoverflies to approach possible mates, and the dragonflies to approach rivals when defending territories. Motion camouflage is achieved by moving so as to stay on a straight line between the target and a fixed point in the landscape; the pursuer thus appears not to move, but only to Looming, loom larger in the target's field of vision. The same method can be used for military purposes, for example by missiles to minimise their risk of detection by an enemy. However, missile engineers, and animals such as bats, use the method mainly for its efficiency rather than camouflage. File:Hoverfly August 2007-8.jpg, Male ''Syritta pipiens'' hoverflies use motion camouflage to approach females File:Australian Emperor mating and laying.jpg, Male Australian Emperor dragonflies use motion camouflage to approach rivals.


Changeable skin coloration

Animals such as
chameleon Chameleons or chamaeleons (Family (biology), family Chamaeleonidae) are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015. These species come in a range of colors, and many species have th ...

chameleon
, frog, flatfish such as the peacock flounder, squid and octopus actively change their skin patterns and colours using special chromatophore cells to resemble their current background, or, as in most chameleons, for
signalling In signal processing Signal processing is an electrical engineering subfield that focuses on analysing, modifying, and synthesizing signals such as audio signal processing, sound, image processing, images, and scientific measurements. Sig ...
. However, Smith's dwarf chameleon does use active colour change for camouflage. Each chromatophore contains pigment of only one colour. In fish and frogs, colour change is mediated by a type of chromatophore known as melanophores that contain dark pigment. A melanophore is star-shaped; it contains many small pigmented organelles which can be dispersed throughout the cell, or aggregated near its centre. When the pigmented organelles are dispersed, the cell makes a patch of the animal's skin appear dark; when they are aggregated, most of the cell, and the animal's skin, appears light. In frogs, the change is controlled relatively slowly, mainly by hormones. In fish, the change is controlled by the brain, which sends signals directly to the chromatophores, as well as producing hormones. The skins of cephalopods such as the octopus contain complex units, each consisting of a chromatophore with surrounding muscle and nerve cells. The cephalopod chromatophore has all its pigment grains in a small elastic sac, which can be stretched or allowed to relax under the control of the brain to vary its opacity. By controlling chromatophores of different colours, cephalopods can rapidly change their skin patterns and colours. On a longer timescale, animals like the Arctic hare, Arctic fox, stoat, and rock ptarmigan have snow camouflage, changing their coat colour (by moulting and growing new fur or feathers) from brown or grey in the summer to white in the winter; the Arctic fox is the only species in the Canidae, dog family to do so. However, Arctic hares which live in the far north of Canada, where summer is very short, remain white year-round. The principle of varying coloration either rapidly or with the changing seasons has military applications. ''Active camouflage'' could in theory make use of both dynamic colour change and counterillumination. Simple methods such as changing uniforms and repainting vehicles for winter have been in use since World War II. In 2011, BAE Systems announced their Adaptiv infrared camouflage technology. It uses about 1,000 hexagonal panels to cover the sides of a tank. The Peltier plate panels are heated and cooled to match either the vehicle's surroundings (crypsis), or an object such as a car (mimesis), when viewed in infrared. File:Rock Ptarmigan (Lagopus Muta).jpg, Rock ptarmigan, changing colour in springtime. The male is still mostly in winter plumage File:Norwegian Winter War Volunteers.jpg, Norwegian volunteer soldiers in Winter War, 1940, with white camouflage overalls over their uniforms File:Arctic Hare.jpg, Arctic hares in the low arctic change from brown to white in winter File:Bundesarchiv Bild 101III-Roth-173-01, Russland, Raum Charkow, Jagdpanzer.jpg, Snow-camouflaged German Marder III jagdpanzer and white-overalled crew and infantry in Russia, 1943 File:Yemen Chameleon (cropped).jpg, Veiled chameleon, ''Chamaeleo calyptratus'', changes colour mainly in relation to mood and for signalling. File:Adaptiv infrared camouflage demo hiding tank as car.jpg, Adaptiv infrared camouflage lets an armoured vehicle mimic a car.


Countershading

Countershading uses graded colour to counteract the effect of self-shadowing, creating an illusion of flatness. Self-shadowing makes an animal appear darker below than on top, grading from light to dark; countershading 'paints in' tones which are darkest on top, lightest below, making the countershaded animal nearly invisible against a suitable background. Thayer observed that "Animals are painted by Nature, darkest on those parts which tend to be most lighted by the sky's light, and ''vice versa''". Accordingly, the principle of countershading is sometimes called ''Thayer's Law''. Countershading is widely used by terrestrial animals, such as gazelles and grasshoppers; marine animals, such as sharks and Delphinus delphis, dolphins; and birds, such as common snipe, snipe and dunlin. Countershading is less often used for military camouflage, despite Second World War experiments that showed its effectiveness. English zoologist Hugh Cott encouraged the use of methods including countershading, but despite his authority on the subject, failed to persuade the British authorities. Soldiers often wrongly viewed camouflage netting as a kind of invisibility cloak, and they had to be taught to look at camouflage practically, from an enemy observer's viewpoint. At the same time in Australia, zoologist William John Dakin advised soldiers to copy animals' methods, using their instincts for wartime camouflage. The term countershading has a second meaning unrelated to "Thayer's Law". It is that the upper and undersides of animals such as sharks, and of some military aircraft, are different colours to match the different backgrounds when seen from above or from below. Here the camouflage consists of two surfaces, each with the simple function of providing concealment against a specific background, such as a bright water surface or the sky. The body of a shark or the fuselage of an aircraft is not gradated from light to dark to appear flat when seen from the side. The camouflage methods used are the matching of background colour and pattern, and disruption of outlines. File:Gazella-dorcas.jpg, Countershaded Dorcas gazelle, ''Gazella dorcas'' File:Tiburón.jpg, Countershaded grey reef shark, ''Carcharhinus amblyrhynchos'' File:Thayers ships.jpg, Countershaded ship and submarine in Abbott Handerson Thayer, Thayer's 1902 patent application File:Abbott thayer countershading.jpg, Two model birds painted by Thayer: painted in background colours on the left, countershaded and nearly invisible on the right File:Focke-Wulf Fw 190D-9 outside USAF.jpg, Countershaded Focke-Wulf Fw 190D-9


Counter-illumination

Counter-illumination means producing light to match a background that is brighter than an animal's body or military vehicle; it is a form of active camouflage. It is notably used by some species of
squid Squid are cephalopod A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are cha ...

squid
, such as the Watasenia scintillans, firefly squid and the Abralia veranyi, midwater squid. The latter has light-producing organs (photophores) scattered all over its underside; these create a sparkling glow that prevents the animal from appearing as a dark shape when seen from below. Counterillumination camouflage is the likely function of the bioluminescence of many marine organisms, though light is also produced to attract or to detect prey and for signalling. Counterillumination has rarely been used for military purposes. "Diffused lighting camouflage" was trialled by Canada's National Research Council (Canada), National Research Council during the Second World War. It involved projecting light on to the sides of ships to match the faint glow of the night sky, requiring awkward external platforms to support the lamps. The Canadian concept was refined in the American Yehudi lights project, and trialled in aircraft including Consolidated B-24 Liberator, B-24 Liberators and naval Grumman TBF Avenger, Avengers. The planes were fitted with forward-pointing lamps automatically adjusted to match the brightness of the night sky. This enabled them to approach much closer to a target – within – before being seen. Counterillumination was made obsolete by radar, and neither diffused lighting camouflage nor Yehudi lights entered active service. File:HMS Largs by night with incomplete Diffused Lighting Camouflage 1942.jpg, HMS Largs, HMS ''Largs'' by night with incomplete diffused lighting camouflage, 1942, set to maximum brightness File:HMS Largs bulwark with Diffused Lighting Camouflage fittings.jpg, Bulwark of HMS ''Largs'' showing 4 (of about 60) diffused lighting fittings, 2 lifted, 2 deployed File:Principle of Yehudi Lights with Avenger head-on view.jpg, Yehudi Lights raise the average brightness of the plane from a dark shape to the same as the sky.


Transparency

Many Sea, marine animals that float near the surface are highly Transparency and translucency, transparent, giving them almost perfect camouflage. However, transparency is difficult for bodies made of materials that have different refractive index, refractive indices from seawater. Some marine animals such as jellyfish have gelatinous bodies, composed mainly of water; their thick Mesoglea, mesogloea is acellular and highly transparent. This conveniently makes them buoyancy, buoyant, but it also makes them large for their muscle mass, so they cannot swim fast, making this form of camouflage a costly trade-off with mobility. Gelatinous planktonic animals are between 50 and 90 percent transparent. A transparency of 50 percent is enough to make an animal invisible to a predator such as cod at a depth of ; better transparency is required for invisibility in shallower water, where the light is brighter and predators can see better. For example, a cod can see prey that are 98 percent transparent in optimal lighting in shallow water. Therefore, sufficient transparency for camouflage is more easily achieved in deeper waters. Some tissues such as muscles can be made transparent, provided either they are very thin or organised as regular layers or fibrils that are small compared to the wavelength of visible light. A familiar example is the transparency of the lens of the vertebrate eye, which is made of the protein crystallin, and the vertebrate cornea which is made of the protein collagen. Other structures cannot be made transparent, notably the retinas or equivalent light-absorbing structures of eyes – they must absorb light to be able to function. The camera-type eye of vertebrates and cephalopods must be completely opaque. Finally, some structures are visible for a reason, such as to lure prey. For example, the nematocysts (stinging cells) of the transparent siphonophore ''Agalma okenii'' resemble small copepods. Examples of transparent marine animals include a wide variety of larvae, including radiata (coelenterates), siphonophores, salps (floating tunicates), gastropoda, gastropod molluscs, polychaete worms, many shrimplike crustaceans, and fish; whereas the adults of most of these are opaque and pigmented, resembling the seabed or shores where they live. Adult comb jelly, comb jellies and jellyfish obey the rule, often being mainly transparent. Cott suggests this follows the more general rule that animals resemble their background: in a transparent medium like seawater, that means being transparent. The small Amazon river fish ''Microphilypnus amazonicus'' and the shrimps it associates with, ''Pseudopalaemon gouldingi'', are so transparent as to be "almost invisible"; further, these species appear to select whether to be transparent or more conventionally mottled (disruptively patterned) according to the local background in the environment.


Silvering

Where transparency cannot be achieved, it can be imitated effectively by silvering to make an animal's body highly reflective. At medium depths at sea, light comes from above, so a mirror oriented vertically makes animals such as fish invisible from the side. Most fish in the upper ocean such as sardine and herring are camouflaged by silvering. The marine hatchetfish is extremely flattened laterally, leaving the body just millimetres thick, and the body is so silvery as to resemble aluminium foil. The mirrors consist of microscopic structures similar to those used to provide structural coloration: stacks of between 5 and 10 crystals of guanine spaced about of a wavelength apart to interfere constructively and achieve nearly 100 per cent reflection. In the deep waters that the hatchetfish lives in, only blue light with a wavelength of 500 nanometres percolates down and needs to be reflected, so mirrors 125 nanometres apart provide good camouflage. In fish such as the herring which live in shallower water, the mirrors must reflect a mixture of wavelengths, and the fish accordingly has crystal stacks with a range of different spacings. A further complication for fish with bodies that are rounded in cross-section is that the mirrors would be ineffective if laid flat on the skin, as they would fail to reflect horizontally. The overall mirror effect is achieved with many small reflectors, all oriented vertically. Silvering is found in other marine animals as well as fish. The cephalopods, including squid, octopus and cuttlefish, have multilayer mirrors made of protein rather than guanine.


Ultra-blackness

Some deep sea fishes have very black skin, reflecting under 0.5% of ambient light. This can prevent detection by predators or prey fish which use bioluminescence for illumination. ''Oneirodes'' had a particularly black skin which reflected only 0.044% of 480 nm wavelength light. The ultra-blackness is achieved with a thin but continuous layer of particles in the dermis, melanosomes. These particles both absorb most of the light, and are sized and shaped so as to scatter rather than reflect most of the rest. Modelling suggests that this camouflage should reduce the distance at which such a fish can be seen by a factor of 6 compared to a fish with a nominal 2% reflectance. Species with this adaptation are widely dispersed in various orders of the phylogenetic tree of bony fishes (Actinopterygii), implying that
natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype right , Here the relation between genotype and phenotype is illustrated, using a Punnett square, for the character of peta ...
has driven the convergent evolution of ultra-blackness camouflage independently many times.


Mimesis

In Mimesis (biology), mimesis (also called ''masquerade''), the camouflaged object looks like something else which is of no special interest to the observer. Mimesis is common in prey animals, for example when a peppered moth caterpillar mimics a twig, or a grasshopper mimics a dry leaf. It is also found in nest structures; some eusocial wasps, such as ''Leipomeles dorsata'', build a nest envelope in patterns that mimic the leaves surrounding the nest. Mimesis is also employed by some predation, predators and parasites to lure their prey. For example, a flower mantis mimics a particular kind of flower, such as an orchid. This tactic has occasionally been used in warfare, for example with heavily armed Q-ships disguised as merchant ships. The common cuckoo, a brood parasite, provides examples of mimesis both in the adult and in the egg. The female lays her eggs in nests of other, smaller species of bird, one per nest. The female mimics a Eurasian sparrowhawk, sparrowhawk. The resemblance is sufficient to make small birds take action to avoid the apparent predator. The female cuckoo then has time to lay her egg in their nest without being seen to do so. The cuckoo's egg itself mimics the eggs of the host species, reducing its chance of being rejected. File:Biston betularia.png, Peppered moth caterpillars mimic twigs File:Insect camouflage PP08338.png, Flower mantis lures its insect prey by mimicking a ''Phalaenopsis'' orchid blossom File:Hooded Grasshopper (Teratodus monticollis) W IMG 0525.jpg, Hooded grasshopper ''Teratodus monticollis'', superbly mimics a leaf with a bright orange border File:Gumleaf grasshopper.jpg, This grasshopper hides from predators by mimicking a dry leaf File:IWM-E-18461-Crusader-camouflaged-19421026.jpg, WWII tank concealed in Operation Bertram by mimicking a truck File:HMS President - geograph.org.uk - 659583.jpg, Armed WW1 Q-ship lured enemy submarines by mimicking a Cargo ship, merchantman File:European Cuckoo Mimics Sparrowhawk.jpg, common cuckoo, Cuckoo adult mimics Eurasian sparrowhawk, sparrowhawk, giving female time to lay eggs parasitically File:Cuckoo Eggs Mimicking Reed Warbler Eggs.JPG, Cuckoo eggs mimicking smaller eggs, in this case of Eurasian reed warbler, reed warbler File:Wrap-around spider in the genus Dolophones (Family Araneidae) Camouflage View.JPG, Wrap-around spider ''Dolophones'' mimicking a stick


Motion dazzle

Most forms of camouflage are made ineffective by movement: a deer or grasshopper may be highly cryptic when motionless, but instantly seen when it moves. But one method, motion dazzle, requires rapidly moving bold patterns of contrasting stripes. Motion dazzle may degrade predators' ability to estimate the prey's speed and direction accurately, giving the prey an improved chance of escape. Motion dazzle distorts speed perception and is most effective at high speeds; stripes can also distort perception of size (and so, perceived range to the target). As of 2011, motion dazzle had been proposed for military vehicles, but never applied. Since motion dazzle patterns would make animals more difficult to locate accurately when moving, but easier to see when stationary, there would be an evolutionary trade-off between motion dazzle and crypsis. An animal that is commonly thought to be dazzle-patterned is the zebra. The bold stripes of the zebra have been claimed to be disruptive camouflage, background-blending and countershading. After many years in which the purpose of the coloration was disputed, an experimental study by Tim Caro suggested in 2012 that the pattern reduces the attractiveness of stationary models to biting flies such as Horse-fly, horseflies and Tsetse fly, tsetse flies. However, a simulation study by Martin How and Johannes Zanker in 2014 suggests that when moving, the stripes may confuse observers, such as mammalian predators and biting insects, by two visual illusions: the wagon-wheel effect, where the perceived motion is inverted, and the barberpole illusion, where the perceived motion is in a wrong direction.


Applications


Military


Before 1800

Ship camouflage was occasionally used in ancient times. Philostratus () wrote in his ''Imagines (work by Philostratus), Imagines'' that Mediterranean pirate ships could be painted blue-gray for concealment. Publius Flavius Vegetius Renatus, Vegetius () says that "Venetian blue" (sea green) was used in the Gallic Wars, when Julius Caesar sent his ''speculatoria navigia'' (reconnaissance boats) to gather intelligence along the coast of Britain; the ships were painted entirely in bluish-green wax, with sails, ropes and crew the same colour. There is little evidence of military use of camouflage on land before 1800, but two unusual ceramics show men in Peru's Mochica culture from before 500 AD, hunting birds with blowpipes which are fitted with a kind of shield near the mouth, perhaps to conceal the hunters' hands and faces. Another early source is a 15th-century French manuscript, ''The Hunting Book of Gaston Phebus'', showing a horse pulling a cart which contains a hunter armed with a crossbow under a cover of branches, perhaps serving as a hide for shooting game. Jamaican Maroons are said to have used plant materials as camouflage in the First Maroon War ().


19th-century origins

The development of military camouflage was driven by the increasing range and accuracy of infantry firearms in the 19th century. In particular the replacement of the inaccurate
musket s aboard the frigate A frigate () is a type of warship, having various sizes and roles over time. In the 17th century, a frigate was any warship built for speed and maneuverability, the description often used being "frigate-built". These co ...
with weapons such as the Baker rifle made personal concealment in battle essential. Two Napoleonic Wars, Napoleonic War skirmishing units of the British Army, the Rifle Brigade (Prince Consort's Own), 95th Rifle Regiment and the 60th Rifle Regiment, were the first to adopt camouflage in the form of a rifle green jacket, while the Line regiments continued to wear scarlet tunics. A contemporary study in 1800 by the English artist and soldier Charles Hamilton Smith provided evidence that grey uniforms were less visible than green ones at a range of 150 yards. In the American Civil War, rifle units such as the 1st United States Sharp Shooters (in the Union (American Civil War), Federal army) similarly wore green jackets while other units wore more conspicuous colours. The first British Army unit to adopt khaki (colour), khaki uniforms was the Corps of Guides (British India), Corps of Guides at Peshawar, when Harry Burnett Lumsden, Sir Harry Lumsden and his second in command, William Stephen Raikes Hodson, William Hodson introduced a "drab" uniform in 1848. Hodson wrote that it would be more appropriate for the hot climate, and help make his troops "invisible in a land of dust". Later they improvised by dyeing cloth locally. Other regiments in India soon adopted the khaki uniform, and by 1896 khaki drill uniform was used everywhere outside Europe; by the Second Boer War six years later it was used throughout the British Army. During the late 19th century camouflage was applied to British coastal fortifications. The fortifications around Plymouth, England were painted in the late 1880s in "irregular patches of red, brown, yellow and green." From 1891 onwards British coastal artillery was permitted to be painted in suitable colours "to harmonise with the surroundings" and by 1904 it was standard practice that artillery and mountings should be painted with "large irregular patches of different colours selected to suit local conditions."


First World War

In the
First World War World War I, often abbreviated as WWI or WW1, also known as the First World War or the Great War, was a that began on 28 July 1914 and ended on 11 November 1918. It involved much of , as well as , the and , and was also fought ...
, the French army formed a camouflage corps, led by Lucien-Victor Guirand de Scévola, employing artists known as ''List of camoufleurs, camoufleurs'' to create schemes such as tree observation posts and covers for guns. Other armies soon followed them. The term ''wikt:camouflage, camouflage'' probably comes from ''camoufler'', a Parisian slang term meaning ''to disguise'', and may have been influenced by ''camouflet'', a French language, French term meaning ''smoke blown in someone's face''. The English zoologist John Graham Kerr, artist Solomon J. Solomon and the American artist Abbott Thayer led attempts to introduce scientific principles of countershading and disruptive patterning into military camouflage, with limited success. In early 1916 the Royal Naval Air Service began to create dummy air fields to draw the attention of enemy planes to empty land. They created decoy homes and lined fake runways with flares, which were meant to help protect real towns from night raids. This strategy was not common practice and did not succeed at first, but in 1918 it caught the Germans off guard multiple times. Ship camouflage was introduced in the early 20th century as the range of naval guns increased, with ships painted grey all over. In April 1917, when German U-boats were sinking many British ships with torpedoes, the marine artist Norman Wilkinson (artist), Norman Wilkinson devised dazzle camouflage, which paradoxically made ships more visible but harder to target. In Wilkinson's own words, dazzle was designed "not for low visibility, but in such a way as to break up her form and thus confuse a submarine officer as to the course on which she was heading". File:USS West Mahomet (ID-3681) cropped.jpg, USS ''West Mahomet'' in dazzle camouflage File:CamouflagedAustralian9.2inchHowitzerYpres1917.jpeg, BL 9.2-inch howitzer, Siege howitzer camouflaged against observation from the air, 1917 File:Austro-Hungarian ski patrol on Italian front in snow camouflage 1915-1918.jpg, Austro-Hungarian ski patrol in two-part snow uniforms with improvised head camouflage on Italian front, 1915-1918


Second World War

In the
Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a that lasted from 1939 to 1945. It involved —including all of the great powers—forming two opposing s: the and the . In a total war directly involving m ...
, the zoologist Hugh Cott, a protégé of Kerr, worked to persuade the British army to use more effective camouflage methods, including countershading, but, like Kerr and Thayer in the First World War, with limited success. For example, he painted two rail-mounted coastal guns, one in conventional style, one Countershading, countershaded. In aerial photographs, the countershaded gun was essentially invisible. The power of aerial observation and attack led every warring nation to camouflage targets of all types. The Soviet Union's Red Army created the comprehensive military doctrine, doctrine of ''Russian military deception, Maskirovka'' for military deception, including the use of camouflage. For example, during the Battle of Kursk, Mikhail Katukov, General Katukov, the commander of the Soviet 1st Tank Army, remarked that the enemy "did not suspect that our well-camouflaged tanks were waiting for him. As we later learned from prisoners, we had managed to move our tanks forward unnoticed". The tanks were concealed in previously prepared defensive emplacements, with only their turrets above ground level. In the air, Second World War fighters were often painted in ground colours above and sky colours below, attempting two different camouflage schemes for observers above and below. Bombers and night fighters were often black, while maritime reconnaissance planes were usually white, to avoid appearing as dark shapes against the sky. For ships, dazzle camouflage was mainly replaced with plain grey in the Second World War, though experimentation with colour schemes continued. As in the First World War, artists were pressed into service; for example, the surrealist painter Roland Penrose became a lecturer at the newly founded Camouflage Development and Training Centre at Farnham Castle, writing the practical ''Home Guard Manual of Camouflage''. The film-maker Geoffrey Barkas ran the Middle East Command Camouflage Directorate during the 1941–1942 war in the Western Desert, including the successful deception of Operation Bertram. Hugh Cott was chief instructor; the artist camouflage officers, who called themselves ''camoufleurs'', included Steven Sykes (artist), Steven Sykes and Tony Ayrton. In Australia, artists were also prominent in the Sydney Camouflage Group, formed under the chairmanship of Professor William John Dakin, a zoologist from Sydney University. Max Dupain, Sydney Ure Smith, and William Dobell were among the members of the group, which worked at Bankstown Airport, RAAF Base Richmond and Garden Island Dockyard. In the United States, artists like John Vassos took a certificate course in military and industrial camouflage at the American School of Design with Baron Nicholas Cerkasoff, and went on to create camouflage for the Air Force. File:Catalina Góraszka 2008 204.JPG, Maritime patrol Consolidated PBY Catalina, Catalina, painted white to minimise visibility against the sky File:SS Platanenmuster Sommer.jpg, 1937 summer variant of Waffen SS ''Flecktarn'' Plane tree pattern File:USS Duluth (CL-87) underway in Hampton Roads on 10 October 1944 (NH 98363).jpg, USS Duluth (CL-87), USS ''Duluth'' in naval camouflage Measure 32, Design 11a, one of many dazzle schemes used on warships File:Spitfire.planform.arp.jpg, A Supermarine Spitfire, Spitfire's underside 'azure' paint scheme, meant to hide it against the sky File:Royal Air Force 1939-1945- Fighter Command CL3979.jpg, A Luftwaffe aircraft hangar built to resemble a street of village houses, Belgium, 1944 File:Bundesarchiv Bild 183-E0406-0022-001, Russland, Kesselschlacht Stalingrad.jpg, Red Army soldiers in the Battle of Stalingrad in snow camouflage overalls, January 1943


After 1945

Camouflage has been used to protect military equipment such as vehicles, guns, Ship camouflage, ships, Aircraft camouflage, aircraft and buildings as well as individual soldiers and their positions. Vehicle camouflage methods begin with paint, which offers at best only limited effectiveness. Other methods for stationary land vehicles include covering with improvised materials such as blankets and vegetation, and erecting nets, screens and soft covers which may suitably reflect, scatter or absorb near infrared and radar waves. Some military textiles and vehicle camouflage paints also reflect infrared to help provide concealment from image intensification, night vision devices. After the Second World War, radar made camouflage generally less effective, though coastal boats are sometimes painted like land vehicles. Aircraft camouflage too came to be seen as less important because of radar, and aircraft of different air forces, such as the Royal Air Force's English Electric Lightning, Lightning, were often uncamouflaged. Many List of camouflage patterns, camouflaged textile patterns have been developed to suit the need to match Battledress, combat clothing to different kinds of terrain (such as woodland, snow, and desert). The design of a pattern effective in all terrains has proved elusive. The American Universal Camouflage Pattern of 2004 attempted to suit all environments, but was withdrawn after a few years of service. Terrain-specific patterns have sometimes been developed but are ineffective in other terrains. The problem of making a pattern that works at different ranges has been solved with multiscale designs, often with a pixellated appearance and designed digitally, that provide a fractal-like range of patch sizes so they appear disruptively coloured both at close range and at a distance. The first genuinely digital camouflage pattern was the Canadian Disruptive Pattern (CADPAT), issued to the army in 2002, soon followed by the American Marine pattern (MARPAT). A pixellated appearance is not essential for this effect, though it is simpler to design and to print. File:CADPAT digital camouflage pattern (Temperate Woodland variant).jpg, CADPAT was the first pixellated digital camouflage pattern to be issued, in 2002. File:British dpm2.jpg, British Disruptive Pattern Material, issued to Special forces#United Kingdom, special forces in 1963 and universally by 1968 File:M05 snow pattern.jpg, 2007 2-colour snow variant of Finnish Defence Forces M05 pattern File:Pla camo.svg, Main (4-colour woodland) variant of People's Republic of China, Chinese People's Liberation Army Type 99 (camouflage), Type 99 pattern, c. 2006