List of ways of hiding objects or animals in plain sight
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.
Conventions used
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.
Comparisons
Examples of camouflage methods in animal and military usage
Side or Thayercountershading: 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
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]
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
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
^Barlow, G. W. (1972). "The attitude of fish eye-lines in relation to body shape and to stripes and bars". Copeia. 1972 (1): 4–12. doi:10.2307/1442777. JSTOR1442777.
^Middle East AFV Technical Letter. The Tank Museum, UK; originally G(Cam) Eighth Army. 26 January 1945.
^Bush, Vannevar; Conant, James; Harrison, George; et al. (1946). Camouflage of Sea-Search Aircraft(PDF). Office of Scientific Research and Development, National Defence Research Committee. pp. 225–240. Archived from the original(PDF) on October 23, 2013. Retrieved 12 February 2013. {{cite book}}: |work= ignored (help)
^Stephenson, Hubert Kirk. (1948) Applied Physics, pp. 200, 258. Science in World War II; Office of Scientific Research and Development. Volume 6 of Science in World War II (Atlantic Monthly Press Book). Editors: Chauncey Guy Suits and George Russell Harrison. Little, Brown.
Bibliography
Barkas, Geoffrey; Barkas, Natalie (1952). The Camouflage Story (from Aintree to Alamein). Cassell.
Beddard, Frank Evers (1892). Animal Coloration: an account of the principal facts and theories relating to the colours and markings of animals. Swan Sonnenschein.