Camouflage

This article is about protective coloration. For other uses, see Camouflage (disambiguation).

Further information: Theory of camouflage

A flounder blending in with the gravel on the sea floor.

Camouflage is a method of crypsis (hiding). It allows an otherwise visible organism or object to remain unnoticed, by blending with its environment. Examples include a tiger's stripes, the battledress of a modern soldier and a butterfly camouflaging itself as a leaf. The theory of camouflage covers the various strategies used to achieve this effect.

In nature

Hooded grasshopper

Further information: Crypsis, Antipredator adaptation, and Animal coloration

Animal camouflage techniques

Animals camouflage themselves in several different ways:^[1]:

• Mimesis: the whole animal looks like some other object.^[1]
  • In many prey animals, for example when a caterpillar resembles a twig or a bird dropping.^[1]
  • In a few predators (or parasites), luring the prey to approach, for example when a flower mantis resembles a particular kind of flower, such as an orchid^[1]

• Crypsis: the animal's texture blends with the background, making it hard to see, for example when a moth's colour and pattern blend in with tree bark.^[1]
  • Some animals actively seek to make themselves cryptic, using materials such as twigs, sand, or pieces of shell to conceal its outline, for example when a Caddis Fly larva builds a decorated case, or when a crab decorates its back with seaweed, sponges and stones^[1]
  • animals such as chameleon, flatfish, squid or octopus change their skin patterns and colours using special chromatophore cells to resemble whatever background they are currently resting on (as well as for signalling).^[1] See also Category:Animals that can change color.
  • Countershading, using graded color to create the illusion of flatness. Shadow makes an animal lightest on top, darkest below; countershading 'paints in' tones darkest on top, lightest below, making the countershaded animal nearly invisible against a matching background.^[2], and against a matching background, of invisibility. American artist Abbott Handerson Thayer's observation "Animals are painted by Nature, darkest on those parts which tend to be most lighted by the sky's light, and vice versa" is called Thayer's Law.^[3] Examples include deer and sharks.

Mechanisms of color production in animals

Animals produce camouflage colors in several ways: ^[4]

1. Pigments (colored chemicals such as melanin) deposited by cells called melanocytes into skin, fur and feathers.^[4] For example, the Arctic fox has a white coat in winter (containing little pigment), and a brown coat in summer (containing more pigment).
2. Chromatophores, special pigment-containing cells that can change their size, so varying the color and pattern of the animal.^[4] For example, cuttlefish and chameleons can rapidly change their appearance for camouflage and for signalling.
3. Microscopically-structured surfaces fine enough to interfere with visible light, and so creating brilliant colors, often iridescent.^[4] For example, the blue/green gloss on the plumage of birds such as ducks, and the purple/blue/green/red colours of many beetles and butterflies are created by interference.

Gallery

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  Gumleaf grasshopper, so named because of its mimicry of dead leaves

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  Hoplophrys oatesii crab hiding in a soft coral‎ from East Timor

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  An arctic hare's white colouration camouflages it in the snow

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  Wall lizard well adapted to hiding in the Saharan sand

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  Camouflage allows predator to capture prey

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  The Egyptian Nightjar nests in the open sand with only its colouration to protect it

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  Scorpion fish resting beside a rope

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  A mackerel tabby cat blending with its (autumn) environment

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  Crab with red algae covering its body at Moss Beach, California

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  Countershaded Ibex are almost invisible in the Israeli desert.

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  A Bobcat blends with its winter surroundings, at Almaden Quicksilver County Park

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  Chameleon, Usambara mountains, Tanzania

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  Great male Leopard, made in Sabi Sands Private Game Reserve, South Africa

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  Tawny frogmouths in tree

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  Insect looking like a green leaf

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  Zebras appear strikingly patterned to humans, but not to lions.

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  A Leaf Insect in the permanent collection of The Children’s Museum of Indianapolis

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  A Papuan Frogmouth in a tree, Daintree River, Queensland, Australia

In military use

A camouflaged sniper, an example of military camouflage

A camouflaged Marine in Afghanistan

Main article: Military camouflage

Early military use

Military camouflage was not in wide use before the 20th century. 18th and 19th century armies tended to use bright colors and bold, impressive designs. These were intended to daunt the enemy, attract recruits, foster unit cohesion, or allow easier identification of units in the fog of war common to the battlefield before the invention of smokeless propellants.^{[citation needed]}

Jäger riflemen in the 18th century were the first to adopt colors in relatively drab shades of green or grey.^{[citation needed]} In 1857, the British in India chose to dye its white hot-weather uniforms to neutral tones, initially a muddy tan called khaki (from the Urdu word for 'dust') as a temporary measure.^{[citation needed]} It was not until after the Second Boer War that, in 1902, the "home service" (i.e. non-tropical) field uniforms of the entire British army were standardised using a darker shade of khaki serge.^{[citation needed]} Other armies, such as those of the United States, Russia, Italy, and Germany followed suit with khaki, grey, blue-grey or other colors more suitable for their environments, including white for use in snow.^{[citation needed]}

Dazzle camouflage was used on ships during WWI, not to make vessels hard to see, but to make their speed and direction difficult to ascertain by eye.^{[citation needed]}

In World War II, zoologists advised allied armies on camouflage. In England and North Africa, Hugh B. Cott encouraged the use of techniques including Countershading to provide effective concealment, observing that soldiers viewed camouflage netting as "some kind of invisibility cloak: just throw it over the truck and now you don't see it", as Peter Forbes comments.^[5] In Australia William John Dakin advised soldiers to copy animals' methods, using their instincts for wartime camouflage.^[6]

Camouflage technologies

Camouflage netting, natural materials, disruptive color patterns, and paint with special infrared, thermal, and radar qualities are used on military vehicles, ships, aircraft, installations and buildings.^{[citation needed]}

A new development is the use of pixelated patterns of so-called digital camouflage, such as ACUPAT, MARPAT and CADPAT.^[7]

Gallery

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  US Marines in camouflage during a training mission.

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  British soldier during Operation Granby

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  APC painted with a camouflaging pattern

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  A naval ship camouflaged to confuse the enemy and reduce visibility at sea

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  A patrol in winter camouflage during the Battle of the Bulge

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  A camouflaged helicopter

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  German flecktarn camouflage pattern

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  A soldier applies camouflaging face paint

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  Camouflage sniper team
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  IDF Combat Engineering Corps camouflage suit

Non-military applications

A modern deer hunter

Communications tower, camouflaged as a slim tree

Hunters often use camouflage clothing that is visually tailored to the game they are hunting. The most striking example of this is the blaze orange camouflage, which makes the hunter obvious to humans but relies on the fact that most large game animals, such as deer, are dichromats, and perceive the orange as a dull color. On the other hand, optical brighteners, commonly used in laundry detergents to make the laundered items appear brighter, are visible to many game animals; using these will cause what appears to the human eye to be cryptically colored clothing to stand out against the background, when viewed by an animal with ultraviolet-sensitive eyes.^[8]

There are several different types of hunting camouflage. The use of each one is dependent upon the area in which the hunter is going to hunt. It can range in appearance from a mossy oak pattern to a sage brush pattern for hunters of large mammals. Waterfowl hunters can have camouflage that resembles swamp reeds.

See also

• Active camouflage
• Animal coloration
• Aposematism
• Motion camouflage
• Underwater camouflage and mimicry

References

Notes

1. ^ ^{a b c d e f g} Forbes, P. 2009 p. 50-51
2. ^ Cott, H. B. 1940
3. ^ Forbes, P. 2009 p. 72-3
4. ^ ^{a b c d} Wallin, Margareta (2002). "Nature's Palette". Nature's Palett: How animals, including humans, produce colours. Bioscience-explained.org. pp. Vol 1, No 2, pages 1-12. http://www.bioscience-explained.org/ENvol1_2/pdf/paletteEN.pdf. Retrieved November 17, 2011. 
5. ^ Peter Forbes, 2009, page 152.
6. ^ Elias, Ann,"'Camouflage Australia: Art, Nature, Science and War'". http://purl.library.usyd.edu.au/sup/9781920899738. (Sydney: "Sydney University Press". http://sydney.edu.au/sup/. , 2011), pp. 57-66.
7. ^ Barcott, Bruce, "Invisible, Inc.", The Atlantic, 1 July 2011, p. 80.
8. ^ "How Game Animals See and Smell". http://www.atsko.com/articles/hunting/how-game-animals-see-smell.html. 

Bibliography

Camouflage in nature

Pioneering research

• Hugh Cott (1940) Adaptive Coloration in Animals. Methuen, London.
• E. B. Poulton (1890) The colours of Animals. London.
• Abbott Handerson Thayer and G. H. Thayer (1909) Concealing Colouration in the Animal Kingdom. New York.

Recent research

• Martin Stevens and Sami Merilaita (editors). Animal Camouflage: Mechanisms and Function. Cambridge University Press, 2011.

General reading

• Peter Forbes. Dazzled and Deceived: Mimicry and Camouflage. Yale, 2009.
• Wickler, W. Mimicry in plants and animals. McGraw-Hill, 1968.

Children's books

• B. Kalman and J. Crossingham. What are Camouflage and Mimicry?. Crabtree Publishing. (ages 4-8)
• Rene Mettler. Animal Camouflage. Moonlight Publishing. First Discovery series, 2001. (ages 4-8)

Military camouflage

General reading

• Roy Behrens. False Colors: Art, Design and Modern Camouflage. Bobolink Books, 2002.
• Henrietta Gooden. Camouflage and Art: Design for Deception in World War 2. Unicorn Press, 2009.
• Jon Latimer, Deception in War, London: John Murray, 2001.
• Newark, Tim. Camouflage. Thames and Hudson, with Imperial War Museum, 2007.

External links

• Roy R. Behrens, "The Thinking Eye: a Chronology of Camouflage" 2006
• "An informal study into camouflage"
• Octopus camouflage video