View source for Camouflage

{{Short description|Concealment in plain sight by any means, e.g. colour, pattern and shape}}
{{About|a form of protective coloration}}
{{Good article}}
{{EngvarB|date=July 2022}}
{{Use dmy dates|date=July 2022}}
[[File:Flower flounder in Kona may 2010.jpg|thumb|upright=1.35|The [[peacock flounder]] can change its pattern and colours to match its environment.]]
[[File:Maskowanie.JPEG|thumb|upright=1.35|A soldier applying camouflage face paint; both helmet and jacket are [[disruptive coloration|disruptively patterned]].|alt=photo of a soldier putting on camouflage face paint]]
'''Camouflage''' is the use of any combination of materials, color<!--yes, we use "coloration" but not "color" in BE-->ation, 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. 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 transparencying, silveringing, and countershading, while the [[bioluminescence|ability to produce light]] is among other things used for [[counter-illumination]] on the undersides of [[cephalopod]]s such as [[squid]]. Some animals, such as [[chameleon]]s and [[octopus]]es, are capable of [[Active camouflage|actively changing their skin pattern and colors]], whether for camouflage or for signalling. It is possible that some plants use camouflage to evade being eaten by [[herbivore]]s.
[[Military camouflage]] was spurred by the increasing range and accuracy of firearms in the 19th century. In particular the replacement of the inaccurate [[musket]] with the [[rifle]] made personal concealment in battle a survival skill. In the 20th century, military camouflage developed rapidly, especially during the [[First World War]]. On land, artists such as [[André Mare]] designed camouflage schemes and observation posts disguised as trees. [[Ship camouflage|At sea]], merchant ships and troop carriers were painted in [[dazzle camouflage|dazzle]] 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]], a variety of camouflage schemes were used for [[aircraft camouflage|aircraft]] 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 site|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==
[[File:Octopus cyaneain Kona.jpg|thumb|upright=0.8|Octopuses like this ''[[Octopus cyanea]]'' can change colour (and shape) for camouflage]]
In ancient Greece, [[Aristotle]] (384–322 BC) commented on the colour-changing abilities, both for camouflage and for [[Signalling theory|signalling]], of [[cephalopod]]s including the octopus, in his ''[[Historia animalium]]'':<ref name=Aristotle>Aristotle (c. 350 BC). ''Historia Animalium''. IX, 622a: 2–10. Cited in Borrelli, Luciana; [[Francesca Gherardi|Gherardi, Francesca]]; Fiorito, Graziano (2006). ''A catalogue of body patterning in Cephalopoda''. Firenze University Press. {{ISBN|978-88-8453-377-7}}. [http://www.fupress.com/scheda.asp?IDV=487 Abstract] {{Webarchive|url=https://web.archive.org/web/20180206145302/http://classics.mit.edu/Aristotle/history_anim.9.ix.html |date=6 February 2018 }}</ref>
{{Blockquote|The [[octopus]]&nbsp;... seeks its prey by so changing its colour as to render it like the colour of the stones adjacent to it; it does so also [[Deimatic behaviour|when alarmed]].|Aristotle<ref name=Aristotle/>}}
Camouflage has been a topic of interest and research in [[zoology]] for well over a century. According to [[Charles Darwin]]'s 1859 theory of [[natural selection]],{{sfn|Darwin|1859}} features such as camouflage [[evolution|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 his ''[[Origin of Species]]'', Darwin wrote:{{sfn|Darwin|1859|page=84}}
{{Blockquote|When we see leaf-eating insects green, and bark-feeders mottled-grey; the alpine ptarmigan white in winter, the [[red grouse|red-grouse]] the colour of [[Calluna vulgaris|heather]], and the [[black grouse|black-grouse]] that of [[peat]]y earth, we must believe that these tints are of service to these birds and insects in preserving them from danger. Grouse, if not destroyed at some period of their lives, would increase in countless numbers; they are known to suffer largely from [[birds of prey]]; and hawks are guided by eyesight to their prey, so much so, that on parts of the Continent persons are warned not to keep white pigeons, as being the most liable to destruction. Hence I can see no reason to doubt that natural selection might be most effective in giving the proper colour to each kind of grouse, and in keeping that colour, when once acquired, true and constant.{{sfn|Darwin|1859|page=84}}}}
[[File:Variable Protective Resemblance in Lepidopterous Pupae.jpg|thumb|left|upright=1.35|Experiment by [[Edward Bagnall Poulton|Poulton]], 1890: [[Ourapteryx sambucaria|swallowtailed moth]] [[pupa]]e with camouflage they acquired as [[larva]]e]]
The English zoologist [[Edward Bagnall Poulton]] studied [[animal coloration]], especially camouflage. In his 1890 book ''[[The Colours of Animals]]'', 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]] were camouflaged to match the backgrounds on which they were reared as [[larvae]].{{sfn|Poulton|1890|page=111}}{{efn|A letter from [[Alfred Russel Wallace]] to Darwin of 8 March 1868 mentioned such colour change: "Would you like to see the specimens of pupæ of butterflies whose colours have changed in accordance with the colour of the surrounding objects? They are very curious, and Mr. [[T. W. Wood]], who bred them, would, I am sure, be delighted to bring them to show you."<ref>{{cite web |last=Wallace |first=Alfred Russel |author-link=Alfred Russel Wallace |url=http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F1592.1&viewtype=text |title=Alfred Russel Wallace Letters and Reminiscences By James Marchant |publisher=Darwin Online |date=8 March 1868 |access-date=29 March 2013}}</ref>}} Poulton's "general protective resemblance"{{sfn|Poulton|1890|page=Fold-out after p. 339}} 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]]s, [[iguana]]s, [[tree frog|tree-frogs]], and the [[Morelia viridis|green tree-snake]] are examples".{{sfn|Beddard|1892|page=83}} Beddard did however briefly mention other methods, including the "alluring coloration" of the [[Hymenopus bicornis|flower mantis]] and the possibility of a different mechanism in the [[Anthocharis cardamines|orange tip butterfly]]. 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 [an [[umbellifer]]], so close is their mutual resemblance."{{sfn|Beddard|1892|page=87}}{{efn|Cott explains Beddard's observation as a coincident disruptive pattern.{{sfn|Cott|1940|pages=74–75}}}} 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."{{sfn|Beddard|1892|page=122}}
[[File:PeacockInTheWoods.jpg|thumb|upright|[[Abbott Thayer]]'s 1907 painting ''Peacock in the Woods'' depicted a [[peacock]] as if it were camouflaged.]]
The artist [[Abbott Handerson Thayer]] formulated what is sometimes called Thayer's Law, the principle of [[countershading]].{{sfn|Thayer|1909}} However, he overstated the case in the 1909 book ''[[Concealing-Coloration in the Animal Kingdom]]'', 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]]' mark, not one '[[aposematism|warning color]]'...&nbsp;nor any '[[sexual selection|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",{{sfn|Forbes|2009|page=77}}{{sfn|Thayer|1909|pages=5, 16}} and using paintings such as ''Peacock in the Woods'' (1907) to reinforce his argument.{{sfn|Rothenberg|2011|pages=132–133}} Thayer was roundly mocked for these views by critics including [[Theodore Roosevelt|Teddy Roosevelt]].<ref>{{cite journal |last1=Wright |first1=Patrick |title=Cubist Slugs. Review of DPM: Disruptive Pattern Material; An Encyclopedia of Camouflage: Nature – Military – Culture by Roy Behrens |journal=[[London Review of Books]] |date=23 June 2005 |volume=27 |issue=12 |pages=16–20 |url=http://www.lrb.co.uk/v27/n12/patrick-wright/cubist-slugs}}</ref>
The English zoologist [[Cott, H. B.|Hugh Cott]]'s 1940 book ''[[Adaptive Coloration in Animals]]'' 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."{{sfn|Cott|1940|pages=172–173}} 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]] worked, using streaks of boldly contrasting colour, paradoxically making objects less visible by breaking up their outlines.{{sfn|Cott|1940|pages=47–67}} While Cott was more systematic and balanced in his view than Thayer, and did include some experimental evidence on the effectiveness of camouflage,{{sfn|Cott|1940|pages=174–186}} his 500-page textbook was, like Thayer's, mainly a [[natural history]] narrative which illustrated theories with examples.{{sfn|Forbes|2009|pages=153–155}}
Experimental evidence that camouflage helps prey avoid being detected by [[predator]]s was first provided in 2016, when ground-nesting birds ([[plovers]] and [[coursers]]) were shown to survive according to how well their egg contrast matched the local environment.<ref name="TrosciankoWilson-AggarwalStevensSpottiswoode2016">{{cite journal |last1=Troscianko |first1=Jolyon |last2=Wilson-Aggarwal |first2=Jared |last3=Stevens |first3=Martin |author3-link=Martin Stevens (biologist) |last4=Spottiswoode |first4=Claire N. |title=Camouflage predicts survival in ground-nesting birds |journal=Scientific Reports |volume=6 |issue=1 |date=29 January 2016 |doi=10.1038/srep19966 |pmid=26822039 |pmc=4731810 |page=19966 |bibcode=2016NatSR...619966T }}</ref>
==Evolution==
As there is a lack of evidence for camouflage in the fossil record, studying the evolution of camouflage strategies is very difficult. Furthermore, camouflage traits must be both adaptable (provide a fitness gain in a given environment) and heritable (in other words, the trait must undergo [[Directional selection|positive selection]]).<ref>{{Cite journal |last1=Sabeti |first1=P. C. |last2=Schaffner |first2=S. F. |last3=Fry |first3=B. |last4=Lohmueller |first4=J. |last5=Varilly |first5=P. |last6=Shamovsky |first6=O. |last7=Palma |first7=A. |last8=Mikkelsen |first8=T. S. |last9=Altshuler |first9=D. |last10=Lander |first10=E. S. |display-authors=3 |date=2006-06-16 |title=Positive Natural Selection in the Human Lineage |journal=Science |volume=312 |issue=5780 |pages=1614–1620 |doi=10.1126/science.1124309 |pmid=16778047 |bibcode=2006Sci...312.1614S |s2cid=10809290 }}</ref> Thus, studying the evolution of camouflage strategies requires an understanding of the genetic components and various ecological pressures that drive crypsis.
=== Fossil history ===
Camouflage is a soft-tissue feature that is rarely preserved in the [[fossil]] record, but rare fossilised skin samples from the [[Cretaceous]] period show that some marine reptiles were countershaded. The skins, pigmented with dark-coloured [[eumelanin]], reveal that both [[leatherback turtle]]s and [[mosasaur]]s had dark backs and light bellies.<ref>{{cite journal |last1=Lindgren |first1=Johan |last2=Sjövall |first2=Peter |last3=Carney |first3=Ryan M. |last4=Udval |first4=Per |last5=Gren |first5=Johan A. |last6=Dyke |first6=Gareth |last7=Schultz |first7=Bo Pagh |last8=Shawkey |first8=Matthew D. |last9=Barnes |first9=Kenneth R. |last10=Polcyn |first10=Michael J. |display-authors=3 |title=Skin pigmentation provides evidence of convergent melanism in extinct marine reptiles |journal=Nature |date=February 2014 |volume=506 |pages=484–488 |doi=10.1038/nature12899 |pmid=24402224 |issue=7489|bibcode=2014Natur.506..484L |s2cid=4468035 }}</ref> There is fossil evidence of camouflaged insects going back over 100&nbsp;million years, for example lacewings larvae that stick debris all over their bodies much as their modern descendants do, hiding them from their prey.<ref>{{cite web |last=Pavid |first=Katie |title=Oldest insect camouflage behaviour revealed by fossils |url=https://www.nhm.ac.uk/discover/news/2016/june/oldest-insect-camouflage-behaviour-revealed.html |date=28 June 2016}}</ref> Dinosaurs appear to have been camouflaged, as a 120&nbsp;million year old fossil of a ''[[Psittacosaurus]]'' has been preserved with [[countershading]].<ref>{{cite web |last=Watson |first=Traci |title=This Dinosaur Wore Camouflage |website=[[National Geographic Society]] |url=https://www.nationalgeographic.com/news/2016/09/dinosaur-camouflage-fossil-find/ |archive-url=https://web.archive.org/web/20191106232025/https://www.nationalgeographic.com/news/2016/09/dinosaur-camouflage-fossil-find/ |url-status=dead |archive-date=6 November 2019 |date=14 September 2016}}</ref>
=== Genetics ===
Camouflage does not have a single genetic origin. However, studying the genetic components of camouflage in specific organisms illuminates the various ways that crypsis can evolve among lineages.
Many [[cephalopod]]s have the ability to actively camouflage themselves, controlling crypsis through neural activity. For example, the genome of the common cuttlefish includes 16 copies of the [[reflectin]] gene, which grants the organism remarkable control over coloration and iridescence.<ref>{{cite journal |last1=Song |first1=Weiwei |last2=Li |first2=Ronghua |last3=Zhao |first3=Yun |last4=Migaud |first4=Herve |last5=Wang |first5=Chunlin |last6=Bekaert |first6=Michaël |display-authors=3 |date=15 February 2021 |title=Pharaoh Cuttlefish, Sepia pharaonis, Genome Reveals Unique Reflectin Camouflage Gene Set |journal=Frontiers in Marine Science |volume=8 |pages=639670 |doi=10.3389/fmars.2021.639670 |issn=2296-7745|doi-access=free |hdl=1893/32292 |hdl-access=free }}</ref> The reflectin gene is thought to have originated through transposition from symbiotic ''[[Aliivibrio fischeri]]'' bacteria, which provide bioluminescence to its hosts. While not all cephalopods use [[active camouflage]], ancient cephalopods may have inherited the gene horizontally from symbiotic ''A. fischeri'', with divergence occurred through subsequent gene duplication (such as in the case of ''Sepia officinalis'') or gene loss (as with cephalopods with no active camouflage capabilities).<ref>{{cite journal |last1=Guan |first1=Zhe |last2=Cai |first2=Tiantian |last3=Liu |first3=Zhongmin |last4=Dou |first4=Yunfeng |last5=Hu |first5=Xuesong |last6=Zhang |first6=Peng |last7=Sun |first7=Xin |last8=Li |first8=Hongwei |last9=Kuang |first9=Yao |last10=Zhai |first10=Qiran |last11=Ruan |first11=Hao |date=September 2017 |title=Origin of the Reflectin Gene and Hierarchical Assembly of Its Protein |journal=[[Current Biology]] |volume=27 |issue=18 |pages=2833–2842.e6 |doi=10.1016/j.cub.2017.07.061|pmid=28889973 |s2cid=9974056 |doi-access=free |bibcode=2017CBio...27E2833G }}</ref><sup>[3]</sup> This is unique as an instance of camouflage arising as an instance of [[horizontal gene transfer]] from an [[endosymbiont]]. However, other methods of horizontal gene transfer are common in the evolution of camouflage strategies in other lineages. [[Peppered moth]]s  and [[Phasmatodea|walking stick insects]]  both have camouflage-related genes that stem from transposition events.<ref>{{cite journal |last1=van't Hof |first1=Arjen E. |last2=Campagne |first2=Pascal |last3=Rigden |first3=Daniel J. |last4=Yung |first4=Carl J. |last5=Lingley |first5=Jessica |last6=Quail |first6=Michael A. |last7=Hall |first7=Neil |last8=Darby |first8=Alistair C. |last9=Saccheri |first9=Ilik J. |date=June 2016 |title=The industrial melanism mutation in British peppered moths is a transposable element |url=http://www.nature.com/articles/nature17951 |journal=[[Nature (journal)|Nature]] |volume=534 |issue=7605 |pages=102–105 |doi=10.1038/nature17951 |pmid=27251284 |bibcode=2016Natur.534..102H |s2cid=3989607 |issn=0028-0836}}</ref><ref>{{cite journal |last1=Werneck |first1=Jane Margaret Costa de Frontin |last2=Torres |first2=Lucas |last3=Provance |first3=David Willian |last4=Brugnera |first4=Ricardo |last5=Grazia |first5=Jocelia |date=3 December 2021 |title=First Report of Predation by a Stink Bug on a Walking-Stick Insect with Reflections on Evolutionary Mechanisms for Camouflage |doi=10.21203/rs.2.10812/v1 |s2cid=240967012 }}</ref>
The [[Agouti (coloration)|Agouti]] genes are orthologous genes involved in camouflage across many lineages. They produce yellow and red coloration ([[Melanin#Pheomelanin|phaeomelanin]]), and work in competition with other genes that produce black (melanin) and brown (eumelanin) colours.<ref>{{cite journal |last1=Voisey |first1=Joanne |last2=Van Daal |first2=Angela |date=February 2002 |title=Agouti: from Mouse to Man, from Skin to Fat |url=http://doi.wiley.com/10.1034/j.1600-0749.2002.00039.x |journal=Pigment Cell Research |volume=15 |issue=1 |pages=10–18 |doi=10.1034/j.1600-0749.2002.00039.x|pmid=11837451 }}</ref> In [[Eastern deer mouse|eastern deer mice]], over a period of about 8000 years the single agouti gene developed 9 mutations that each made expression of yellow fur stronger under natural selection, and largely eliminated melanin-coding black fur coloration.<ref>{{cite journal |last1=Pfeifer |first1=Susanne P |last2=Laurent |first2=Stefan |last3=Sousa |first3=Vitor C. |last4=Linnen |first4=Catherine R. |last5=Foll |first5=Matthieu |last6=Excoffier |first6=Laurent |last7=Hoekstra |first7=Hopi E. |last8=Jensen |first8=Jeffrey D. |display-authors=3 |date=2018-01-15 |title=The Evolutionary History of Nebraska Deer Mice: Local Adaptation in the Face of Strong Gene Flow |url=http://dx.doi.org/10.1093/molbev/msy004 |journal=Molecular Biology and Evolution |volume=35 |issue=4 |pages=792–806 |doi=10.1093/molbev/msy004 |pmid=29346646 |pmc=5905656 |issn=0737-4038}}</ref> On the other hand, all black [[Cat|domesticated cats]] have deletions of the agouti gene that prevent its expression, meaning no yellow or red color is produced. The evolution, history and widespread scope of the agouti gene shows that different organisms often rely on orthologous or even identical genes to develop a variety of camouflage strategies.<ref>{{cite journal |last1=Eizirik |first1=Eduardo |last2=Yuhki |first2=Naoya |last3=Johnson |first3=Warren E. |last4=Menotti-Raymond |first4=Marilyn |last5=Hannah |first5=Steven S. |last6=O'Brien |first6=Stephen J. |display-authors=3 |date=March 2003 |title=Molecular Genetics and Evolution of Melanism in the Cat Family |journal=Current Biology |volume=13 |issue=5 |pages=448–453 |doi=10.1016/S0960-9822(03)00128-3 |pmid=12620197 |s2cid=19021807 |doi-access=free |bibcode=2003CBio...13..448E }}</ref>
=== Ecology ===
While camouflage can increase an organism's fitness, it has genetic and energetic costs. There is a trade-off between detectability and mobility. Species camouflaged to fit a specific [[Habitat#Microhabitat types|microhabitat]] are less likely to be detected when in that microhabitat, but must spend energy to reach, and sometimes to remain in, such areas. Outside the microhabitat, the organism has a higher chance of detection. Generalized camouflage allows species to avoid predation over a wide range of habitat backgrounds, but is less effective. The development of generalized or specialized camouflage strategies is highly dependent on the biotic and abiotic composition of the surrounding environment.<ref>{{cite book |last1=Ruxton |first1=Graeme D. |author-link=Graeme Ruxton |url=https://oxford.universitypressscholarship.com/view/10.1093/oso/9780199688678.001.0001/oso-9780199688678-chapter-2 |title=Background matching |last2=Allen |first2=William L. |last3=Sherratt |first3=Thomas N. |last4=Speed |first4=Michael P. |date=2018 |publisher=[[Oxford University Press]] |volume=1 |doi=10.1093/oso/9780199688678.003.0002 |isbn=978-0-19-968867-8 }}</ref>
There are many examples of the tradeoffs between specific and general cryptic patterning. ''[[Phestilla]] melanocrachia'', a species of nudibranch that feeds on [[Scleractinia|stony coral]], utilizes specific cryptic patterning in reef ecosystems. The nudibranch syphons pigments from the consumed coral into the epidermis, adopting the same shade as the consumed coral. This allows the nudibranch to change colour (mostly between black and orange) depending on the coral system that it inhabits. However, ''P. melanocrachia'' can only feed and lay eggs on the branches of host-coral, ''[[Platygyra]] carnosa'', which limits the geographical range and efficacy in nudibranch nutritional crypsis. Furthermore, the nudibranch colour change is not immediate, and switching between coral hosts when in search for new food or shelter can be costly.<ref>{{cite journal |last1=Wong |first1=Kwan Ting |last2=Ng |first2=Tsz Yan |last3=Tsang |first3=Ryan Ho Leung |last4=Ang |first4=Put |date=24 June 2017 |title=First observation of the nudibranch Tenellia feeding on the scleractinian coral Pavona decussata |journal=Coral Reefs |volume=36 |issue=4 |pages=1121 |doi=10.1007/s00338-017-1603-8 |bibcode=2017CorRe..36.1121W |s2cid=33882835 |doi-access=free }}</ref>
The costs associated with distractive or disruptive crypsis are more complex than the costs associated with background matching. Disruptive patterns distort the body outline, making it harder to precisely identify and locate.<ref>{{cite book |last1=Ruxton |first1=Graeme D. |author-link=Graeme Ruxton |url=https://oxford.universitypressscholarship.com/view/10.1093/oso/9780199688678.001.0001/oso-9780199688678-chapter-3 |title=Disruptive camouflage |last2=Allen |first2=William L. |last3=Sherratt |first3=Thomas N. |last4=Speed |first4=Michael P. |date=20 September 2018 |publisher=[[Oxford University Press]] |volume=1 |doi=10.1093/oso/9780199688678.003.0003|isbn=978-0-19-968867-8 }}</ref> However, disruptive patterns result in higher predation.<ref>{{cite journal |last1=Stevens |first1=Martin |author1-link=Martin Stevens (biologist) |last2=Marshall |first2=Kate L. A. |last3=Troscianko |first3=Jolyon |last4=Finlay |first4=Sive |last5=Burnand |first5=Dan |last6=Chadwick |first6=Sarah L. |display-authors=3 |date=2013 |title=Revealed by Conspicuousness: Distractive Markings Reduce Camouflage |journal=Behavioral Ecology |volume=24 |issue=1 |pages=213–222 |doi=10.1093/beheco/ars156 |issn=1465-7279|doi-access=free }}</ref> Disruptive patterns that specifically involve visible symmetry (such as in some butterflies) reduce survivability and increase predation.<ref>{{cite journal |last1=Cuthill |first1=Innes C. |author-link=Innes Cuthill |last2=Hiby |first2=Elly |last3=Lloyd |first3=Emily |date=22 May 2006 |title=The Predation Costs of Symmetrical Cryptic Coloration |journal=Proceedings of the Royal Society B: Biological Sciences |volume=273 |issue=1591 |pages=1267–1271 |doi=10.1098/rspb.2005.3438 |issn=0962-8452 |pmc=1560277 |pmid=16720401}}</ref> Some researchers argue that because wing-shape and color pattern are genetically linked, it is genetically costly to develop asymmetric wing colorations that would enhance the efficacy of disruptive cryptic patterning. Symmetry does not carry a high survival cost for butterflies and moths that their predators views from above on a homogeneous background, such as the bark of a tree. On the other hand, natural selection drives species with variable backgrounds and habitats to move symmetrical patterns away from the centre of the wing and body, disrupting their predators' symmetry recognition.<ref>{{cite journal |last1=Wainwright |first1=J. Benito |last2=Scott-Samuel |first2=Nicholas E. |last3=Cuthill |first3=Innes C. |author3-link=Innes Cuthill |date=15 January 2020 |title=Overcoming the Detectability Costs of Symmetrical Coloration |journal=Proceedings of the Royal Society B: Biological Sciences |volume=287 |issue=1918 |pages=20192664 |doi=10.1098/rspb.2019.2664 |pmc=7003465 |pmid=31937221}}</ref>
==Principles==
{{Further|List of camouflage methods}}
{{multiple image |total_width=300
|image1=2005-Draco-dussumieri.jpg|caption1=''[[Draco dussumieri]]'' uses several methods of camouflage, including disruptive coloration, lying flat, and concealment of shadow.|alt1=photo of a Draco dussumieri on a tree trunk, very hard to see
|image2=Podargus papuensis - Daintree River.jpg|caption2=[[Papuan frogmouth]] resembles a broken branch.
}}
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 [[Olfaction|olfactory]] (scent) and [[Hearing|acoustic]] (sound) detection.<ref name="Conner2014">{{cite book |last=Conner |first=William E. |title=Insect Hearing and Acoustic Communication |chapter=Adaptive Sounds and Silences: Acoustic Anti-Predator Strategies in Insects |series=Animal Signals and Communication |volume=1 |year=2014 |pages=65–79 |issn=2197-7305 |doi=10.1007/978-3-642-40462-7_5 |isbn=978-3-642-40461-0 |quote=adaptive silence, acoustic crypsis, stealth,}}</ref><ref name="Miller Maritz McKay Glaudas p=20152182">{{cite journal | last1=Miller | first1=Ashadee Kay | last2=Maritz | first2=Bryan | last3=McKay | first3=Shannon | last4=Glaudas | first4=Xavier | last5=Alexander | first5=Graham J. | title=An ambusher's arsenal: chemical crypsis in the puff adder (''Bitis arietans'') | journal=Proceedings of the Royal Society B: Biological Sciences | publisher=The Royal Society | volume=282 | issue=1821 | date=2015-12-22 | issn=0962-8452 | doi=10.1098/rspb.2015.2182 | page=20152182 | pmid=26674950 | pmc=4707760 |quote=Field observations of puff adders (''Bitis arietans'') going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (''Canis familiaris'') and meerkats (''Suricata suricatta'') to test whether a canid and a herpestid predator could detect ''B. arietans'' using olfaction. |doi-access=free }}</ref> Methods may also apply to military equipment.<ref name="Costa 2007">{{cite journal |last=Costa |first=James T. |title=How a naturalist found safe colours for soldiers |journal=[[Nature (journal)|Nature]] |volume=448 |issue=7152 |year=2007 |issn=0028-0836 |doi=10.1038/448408c |page=408 |bibcode=2007Natur.448..408C |quote=cryptic coloration in British field uniforms was not fully adopted until the Boer War |doi-access=free }}</ref>
=== Background matching ===
Some animals' colours and patterns match a particular natural background. This is an important component of camouflage in all environments. For instance, tree-dwelling [[parakeet]]s are mainly green; [[woodcock]]s of the forest floor are brown and speckled; reedbed [[bittern]]s are streaked brown and buff; in each case the animal's coloration matches the hues of its habitat.{{sfn|Cott|1940|pages=5–19}}{{sfn|Forbes|2009|page=51}} Similarly, [[Xerocole|desert animals]] are almost all desert coloured in tones of sand, buff, ochre, and brownish grey, whether they are mammals like the [[gerbil]] or [[fennec fox]], birds such as the [[desert lark]] or [[sandgrouse]], or reptiles like the [[skink]] or [[Cerastes (genus)|horned viper]].{{sfn|Cott|1940|pages=5–6}} Military uniforms, too, generally resemble their backgrounds; for example [[khaki]] uniforms are a muddy or dusty colour, originally chosen for service in South Asia.{{sfn|Newark|2007|pages=45–46}} Many moths show [[industrial melanism]],{{sfn|Cott|1940|page=17}} including the [[Biston betularia|peppered moth]] which has coloration that blends in with tree bark.<ref>{{cite book |last=Still |first=J. |title=Collins Wild Guide: Butterflies and Moths |publisher=HarperCollins |year=1996 |page=158 |isbn=978-0-00-220010-3}}</ref> The coloration of these insects [[Peppered moth evolution|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.{{sfn|Cott|1940|page=17}}{{efn|Before 1860, unpolluted tree trunks were often covered in pale [[lichen]]s; polluted trunks were bare, and often nearly black.}} This is taken by zoologists as [[Coloration evidence for natural selection|evidence that camouflage is influenced by natural selection]], as well as demonstrating that it changes where necessary to resemble the local background.{{sfn|Cott|1940|page=17}}
<gallery class="center" mode="nolines" heights="120" widths="150">
File:Lion-in-tall-grass.jpg|Lion in Kruger National Park, South Africa, blending in with the tall grass
File:Tanzania 0607 cropped Nevit.jpg|[[Pterocles decoratus|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:Katydid camouflaged in basil plant.jpg|Bright green [[katydid]] has the colour of fresh vegetation.
</gallery>
===Disruptive coloration===
{{Main|disruptive coloration}}
[[File:Disruptive Coloration by Hugh Cott 1940.jpg|thumb|upright=1.15|Illustration of the principle of "maximum disruptive contrast" by [[Hugh Cott]], 1940]]
Disruptive patterns use strongly contrasting, non-repeating markings such as spots or stripes to break up the outlines of an animal or military vehicle,<ref name=Barbosa>{{cite journal |title=Cuttlefish camouflage: The effects of substrate contrast and size in evoking uniform, mottle or disruptive body patterns |last1=Barbosa |first1=A. |last2=Mathger |first2=L. M. |last3=Buresch |first3=K. C. |author4=Kelly, J. |author5=Chubb, C. |author6=Chiao, C. |author7=Hanlon R. T. |journal=Vision Research |year=2008 |volume=48 |pages=1242–1253 |doi=10.1016/j.visres.2008.02.011 |pmid=18395241 |issue=10|s2cid=16287514 |doi-access=free }}</ref> or to conceal telltale features, especially [[disruptive eye mask|by masking the eyes]], as in the [[common frog]].{{sfn|Cott|1940|pages=83–91}} Disruptive patterns may use more than one method to defeat visual systems such as [[edge detection]].<ref>{{cite web |last1=Osorio |first1=Daniel |last2=Cuthill |first2=Innes C. |author2-link=Innes Cuthill |url=http://www.gestaltrevision.be/pdfs/oxford/Osorio&Cuthill-Camouflage_and_perceptual_organization_in_the_animal_kingdom.pdf |archive-url=https://web.archive.org/web/20131029193153/http://www.gestaltrevision.be/pdfs/oxford/Osorio&Cuthill-Camouflage_and_perceptual_organization_in_the_animal_kingdom.pdf |archive-date=2013-10-29 |url-status=live |title=Camouflage and perceptual organization in the animal kingdom |access-date=25 October 2013}}</ref> Predators like the [[leopard]] use disruptive camouflage to help them approach prey, while potential prey use it to avoid detection by predators.<ref name=Disruptive>{{cite journal |title=Disruptive contrast in animal camouflage |last1=Stevens |first1=Martin |author1-link=Martin Stevens (biologist) |last2=Cuthill |first2=Innes C. |author2-link=Innes Cuthill |author3=Windsor, A. M. M. |author4=Walker, H. J. |journal=Proceedings of the Royal Society B |date=7 October 2006 |volume=273 |issue=1600 |pages=2433–2436 |doi=10.1098/rspb.2006.3614 |pmc=1634902 |pmid=16959632}}</ref> 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.<ref name="Sweet">{{cite book |title=Transportation and Cargo Security: Threats and Solutions |publisher=Prentice Hall |last=Sweet |first=K. M. |year=2006 |page=219 |isbn=978-0-13-170356-8}}</ref><ref name=fm5-20>{{cite book |url=https://archive.org/details/Fm5-201944 |title=FM 5–20: Camouflage, Basic Principles |publisher=U.S. War Department |orig-year=1944 |date=November 2015}}</ref><ref name='FM 20-3'>{{cite book |publisher=Department of the Army |title=Field Manual Headquarters No. 20-3 − Camouflage, Concealment, and Decoys |date=30 August 1999 |url=https://irp.fas.org/doddir/army/attp3-34-39.pdf |archive-url=https://web.archive.org/web/20211117211145/https://irp.fas.org/doddir/army/attp3-34-39.pdf |archive-date=17 November 2021}}</ref>
The presence of bold skin markings does not in itself prove that an animal relies on camouflage, as that depends on its behaviour.<ref name=Roosevelt>{{cite journal |title=Revealing and concealing coloration in birds and mammals |last=Roosevelt |first=Theodore |author-link=Theodore Roosevelt |journal=Bulletin of the American Museum of Natural History |year=1911 |volume=30 |issue=Article 8 |pages=119–231|hdl = 2246/470}} Roosevelt attacks Thayer on page 191, arguing that neither zebra nor giraffe are "'adequately obliterated' by countershading or coloration pattern or anything else."</ref> For example, although [[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.<ref name="Mitchell2003">{{cite journal |author1=Mitchell, G. |author2=Skinner, J. D. |year=2003 |title=On the origin, evolution and phylogeny of giraffes ''Giraffa camelopardalis'' |journal=Transactions of the Royal Society of South Africa |volume=58 |issue=1 |pages=51–73 |doi=10.1080/00359190309519935 |bibcode=2003TRSSA..58...51M |s2cid=6522531 |url=http://www.bringyou.to/GiraffeEvolution.pdf |access-date=26 April 2012 |archive-url=https://web.archive.org/web/20150923194550/http://www.bringyou.to/GiraffeEvolution.pdf |archive-date=23 September 2015 |url-status=dead }}</ref> 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.<ref name="Mitchell2003"/> 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,<ref name="Mitchell2003"/> 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 [[Heredity|inherited]].<ref name="Mitchell2003"/>
The possibility of [[camouflage in plants]] was little studied until the late 20th century. Leaf [[variegation]] with white spots may serve as camouflage in forest [[understory]] 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]]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.<ref name="Lev-Yadun 2003 pp. 483–489">{{cite journal |last=Lev-Yadun |first=Simcha |title=Why do some thorny plants resemble green zebras? |journal=Journal of Theoretical Biology |volume=224 |issue=4 |year=2003 |doi=10.1016/s0022-5193(03)00196-6 |pmid=12957121 |pages=483–489|bibcode=2003JThBi.224..483L }}</ref><ref>{{cite book |last=Lev-Yadun |first=Simcha |year=2006 |title=Defensive coloration in plants: a review of current ideas about anti-herbivore coloration strategies |work=Floriculture, ornamental and plant biotechnology: advances and topical issues. Vol. IV |editor=Teixeira da Silva, J.A. |publisher=Global Science Books |pages=292–299 |isbn=978-4903313092}}</ref><ref name="Givnish1990">{{cite journal |last=Givnish |first=T. J. |title=Leaf Mottling: Relation to Growth Form and Leaf Phenology and Possible Role as Camouflage |journal=Functional Ecology |jstor=2389314 |volume=4 |issue=4 |pages=463–474 |year=1990 |doi=10.2307/2389314 |bibcode=1990FuEco...4..463G }}</ref>
<gallery class="center" mode="nolines" heights="150" widths="150">
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]]'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]]: a disruptively camouflaged invertebrate predator
File:Smilax bona-nox, Colt Creek State Park, Lakeland, Florida.jpg|Many [[understory]] plants such as the saw greenbriar, ''[[Smilax bona-nox]]'' have pale markings, possibly disruptive camouflage.
</gallery>
{{anchor|Fringe}}
===Eliminating shadow===
[[File:Counteracting shadow.svg|thumb|Camouflaged animals and vehicles are readily given away by their shapes and shadows. A flange helps to hide the shadow and a pale fringe breaks up and averages out any shadow that remains.]]
Some animals, such as the [[horned lizard]]s of North America, have evolved elaborate measures to eliminate [[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.<ref name="Sherbrooke">{{cite book |title=Introduction to horned lizards of North America |publisher=University of California Press |last=Sherbrooke |first=W. C. |year=2003 |pages=117–118 |isbn=978-0-520-22825-2 |url=https://books.google.com/books?id=zXlLdu3956gC&pg=PA118}}</ref> 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.<ref name="Sherbrooke"/> Some species of butterflies, such as the speckled wood, ''[[Pararge aegeria]]'', 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.{{sfn|Cott|1940|pages=104–105}} Similarly, some ground-nesting birds, including the [[European nightjar]], select a resting position facing the sun.{{sfn|Cott|1940|pages=104–105}} Eliminating shadow was identified as a principle of military camouflage during the [[Second World War]].<ref name="TTT">{{cite journal |author=U.S. War Department |title=Principles of Camouflage |journal=Tactical and Technical Trends |date=November 1943 |issue=37 |url=http://www.lonesentry.com/articles/ttt09/camouflage.html}}</ref>
{{clear}}
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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.
</gallery>
===Distraction===
{{Main|Distractive markings}}
Many prey animals have conspicuous high-contrast markings which paradoxically attract the predator's gaze.{{efn|These distraction markings are sometimes called dazzle markings, but have nothing to do with motion dazzle or wartime dazzle painting.}}<ref name="StevensMerilaita2009">{{cite journal |last1=Stevens |first1=Martin |author1-link=Martin Stevens (biologist) |last2=Merilaita |first2=S. |title=Defining disruptive coloration and distinguishing its functions |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=364 |issue=1516 |year=2009 |pages=481–488 |doi=10.1098/rstb.2008.0216|pmid=18990673 |pmc=2674077 }}</ref> 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 tit]]s increased when artificial prey had distractive markings.<ref name="DimitrovaStobbe2009">{{cite journal |last1=Dimitrova |first1=M. |last2=Stobbe |first2=N. |last3=Schaefer |first3=H. M. |last4=Merilaita |first4=S.|title=Concealed by conspicuousness: distractive prey markings and backgrounds |journal=Proceedings of the Royal Society B: Biological Sciences |volume=276 |issue=1663 |year=2009 |pages=1905–1910 |doi=10.1098/rspb.2009.0052 |pmid=19324754 |pmc=2674505 }}</ref>
===Self-decoration===
{{Main|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.{{sfn|Forbes|2009|pages=50–51 and passim}} 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 ([[trichome]]s) 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.<ref>{{cite journal |last=Wierauch |first=C. |year=2006 |title=Anatomy of disguise: camouflaging structures in nymphs of Some Reduviidae (Heteroptera) |journal=American Museum Novitates |issue=3542 |pages=1–18 |doi=10.1206/0003-0082(2006)3542[1:AODCSI]2.0.CO;2 |hdl=2246/5820 |s2cid=7894145 |url=http://digitallibrary.amnh.org/bitstream/2246/5820/1//v3/dspace/updateIngest/pdfs/N3542.pdf |archive-url=https://web.archive.org/web/20170816190844/http://digitallibrary.amnh.org/bitstream/2246/5820/1//v3/dspace/updateIngest/pdfs/N3542.pdf |archive-date=2017-08-16 |url-status=live }}</ref><ref>{{cite magazine |last=Bates |first=Mary |title=Natural Bling: 6 Amazing Animals That Decorate Themselves |url=http://news.nationalgeographic.com/2015/06/150610-animals-camouflage-decoration-bugs-science |archive-url=https://web.archive.org/web/20150611230313/http://news.nationalgeographic.com/2015/06/150610-animals-camouflage-decoration-bugs-science/ |url-status=dead |archive-date=11 June 2015 |magazine=National Geographic |access-date=11 June 2015|date=2015-06-10 }}</ref>
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.{{sfn|Forbes|2009|pages=102–103}} 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."{{sfn|Cott|1940|page=360}}<ref>{{Cite journal |last1=Ruxton |first1=Graeme D. |author1-link=Graeme Ruxton |last2=Stevens |first2=Martin |author2-link=Martin Stevens (biologist) |title=The evolutionary ecology of decorating behaviour |journal=Biology Letters |date=1 June 2015 |page=20150325 |volume=11 |issue=6 |doi=10.1098/rsbl.2015.0325 |pmid=26041868 |pmc=4528480 }}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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: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
</gallery>
===Cryptic behaviour===
[[File:Leafy Seadragon Phycodurus eques 2500px PLW edit.jpg|thumb|The [[leafy sea dragon]] sways like seaweeds to reinforce its camouflage.]]
Movement catches the eye of prey animals on the lookout for predators, and of predators hunting for prey.{{sfn|Cott|1940|page=141}} 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.{{sfn|Cott|1940|page=141}} 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.<ref name=Mitchell2003/> 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.<ref name="HLCS">{{cite web |url=http://www.hornedlizards.org/horned-lizards.html |publisher=Horned Lizard Conservation Society |work=hornedlizards.org |title=What is a Horned Lizard? |access-date=14 November 2015}}</ref> In the ocean, the [[leafy sea dragon]] sways mimetically, like the seaweeds amongst which it rests, as if rippled by wind or water currents.<ref name="WWF">{{cite web |url=http://wwf.panda.org/about_our_earth/teacher_resources/best_place_species/current_top_10/leafy_sea_dragon.cfm |title=Leafy Sea Dragon |publisher=WWF |access-date=21 December 2011}}</ref> 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.<ref name="Bian2016">{{cite journal |last1=Bian |first1=Xue |last2=Elgar |first2=Mark A. |last3=Peters |first3=Richard A. |title=The swaying behavior of Extatosoma tiaratum: motion camouflage in a stick insect? |journal=Behavioral Ecology |date=2016 |volume=27 |issue=1 |pages=83–92 |doi=10.1093/beheco/arv125 |doi-access=free }}</ref>
===Motion camouflage===
{{Main|Motion camouflage}}
[[File:Motion Camouflage Principle.svg|thumb|Comparison of motion camouflage and classical pursuit]]
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.{{sfn|Cott|1940|pages=141–143}} However, insects such as [[Hoverfly|hoverflies]]<ref name="Srinivasan and Davey">{{cite journal |title=Strategies for active camouflage of motion |author1=Srinivasan, M. V. |author2=Davey, M. |journal=Proceedings of the Royal Society B |year=1995 |volume=259 |pages=19–25 |issue=1354 |doi=10.1098/rspb.1995.0004|bibcode=1995RSPSB.259...19S |s2cid=131341953 }}</ref> and [[Dragonfly|dragonflies]] use [[motion camouflage]]: the hoverflies to approach possible mates, and the dragonflies to approach rivals when defending territories.<ref name="NatureNews">{{cite journal |url=http://www.nature.com/news/2003/030605/full/news030602-10.html |journal=Nature |title=Dragonfly flight tricks the eye |date=5 June 2003 |access-date=16 January 2012 |last=Hopkin |first=Michael |doi=10.1038/news030602-10 }}</ref><ref name="Mizutani">{{cite journal |title=Insect behaviour: Motion camouflage in dragonflies |author1=Mizutani, A. K. |author2=Chahl, J. S. |author3=Srinivasan, M. V. |journal=Nature |date=5 June 2003 |volume=65 |issue=423 |page=604 |doi=10.1038/423604a|pmid=12789327 |bibcode=2003Natur.423..604M |s2cid=52871328 |doi-access=free }}</ref> 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.<ref name="Glendinning">{{cite journal |pmid=15129957 |pmc=1691618 |year=2004 |last1=Glendinning |first1=P |title=The mathematics of motion camouflage |volume=271 |issue=1538 |pages=477–481 |doi=10.1098/rspb.2003.2622 |journal=Proceedings of the Royal Society B}}</ref>
Some insects sway while moving to appear to be blown back and forth by the breeze.
The same method can be used for military purposes, for example by missiles to minimise their risk of detection by an enemy.<ref name="Srinivasan and Davey"/> However, missile engineers, and animals such as bats, use the method mainly for its efficiency rather than camouflage.<ref name=Ghose>{{cite journal |author1=Ghose, K. |author2=Horiuchi, T. K. |author3=Krishnaprasad, P. S. |author4=Moss, C. F. |title=Echolocating Bats Use a Nearly Time-Optimal Strategy to Intercept Prey |journal=PLOS Biology |volume=4 |issue= 5 |page=e108 |doi=10.1371/journal.pbio.0040108 |year=2006 |pmid=16605303 |pmc=1436025 |doi-access=free }}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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.
File:Motion Camouflage.webm|thumbtime=2|Preying mantises exhibiting motion camouflage.
</gallery>
===Changeable skin coloration===
{{Further|Active camouflage|Snow camouflage}}
Animals such as [[chameleon]], frog,{{sfn|Cott|1940|pages=30–31}} flatfish such as the [[peacock flounder]], squid, octopus and even the isopod [[idotea balthica]] actively change their skin patterns and colours using special [[chromatophore]] cells to resemble their current background, or, as in most chameleons, for [[Signalling theory|signalling]].{{sfn|Forbes|2009|pages=52, 236}} However, [[Smith's dwarf chameleon]] does use active colour change for camouflage.<ref>{{cite journal |last1=Stuart-Fox |first1=Devi |last2=Moussalli |first2=Adnan |last3=Whiting |first3=Martin J. |title=Predator-specific camouflage in chameleons |journal=Biology Letters |date=23 August 2008 |volume=4 |issue=4 |pages=326–9 |doi=10.1098/rsbl.2008.0173 |pmid=18492645 |pmc=2610148 }}</ref>
{{multiple image
|total_width=400px
|align=left
|image1=Peacock Flounder Bothus mancus in Kona.jpg
|caption1=Four frames of the same [[peacock flounder]] taken a few minutes apart, showing its ability to match its coloration to the environment
|image2=Melanophores with dispersed or aggregated melanosomes.svg
|caption2=Fish and frog melanophore cells change colour by moving pigment-containing bodies.
}}
Each chromatophore contains pigment of only one colour. In fish and frogs, colour change is mediated by a type of chromatophore known as [[melanophore]]s that contain dark pigment. A melanophore is star-shaped; it contains many small pigmented [[organelle]]s 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 [[hormone]]s. In fish, the change is controlled by the brain, which sends signals directly to the chromatophores, as well as producing hormones.<ref name="Wallin">{{cite journal |last=Wallin |first=M. |url=http://www.bioscience-explained.org/ENvol1_2/pdf/paletteEN.pdf |archive-url=https://web.archive.org/web/20110722083738/http://www.bioscience-explained.org/ENvol1_2/pdf/paletteEN.pdf |archive-date=2011-07-22 |url-status=live |title=Nature's Palette |journal=Bioscience Explained |year=2002 |access-date=17 November 2011 |volume=1 |issue=2 |pages=1–12}}</ref>
The skins of cephalopods such as the octopus contain complex units, each consisting of a chromatophore with surrounding muscle and nerve cells.{{sfn|Cott|1940|page=32}} 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.<ref name="Cloney">{{cite journal |title=Ultrastructure of Cephalopod Chromatophore Organs |author1=Cloney, R. A. |author2=Florey, E. |journal=Zeitschrift für Zellforschung und Mikroskopische Anatomie |volume=89 |issue=2 |pages=250–280 |year=1968 |pmid=5700268 |doi=10.1007/BF00347297|s2cid=26566732 }}</ref><ref>{{cite web |url=http://marinebio.org/species.asp?id=553 |title=Day Octopuses, Octopus cyanea |publisher=MarineBio Conservation Society |access-date=31 January 2013 |archive-url=https://web.archive.org/web/20160320205031/http://marinebio.org/species.asp?id=553 |archive-date=20 March 2016 |url-status=dead }}</ref>
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.<ref name="Churchill">{{cite web |url=http://churchillpolarbears.org/churchill/arctic-wildlife |title=Arctic Wildlife |publisher=Churchill Polar Bears |year=2011 |access-date=22 December 2011}}</ref> However, Arctic hares which live in the far north of [[Canada]], where summer is very short, remain white year-round.<ref name="Churchill"/><ref name="ParksCanada">{{cite book |title=The Status of Arctic Hare (Lepus arcticus bangsii) in Insular Newfoundland |url=http://www.env.gov.nl.ca/env/wildlife/endangeredspecies/ssac/arctic_hare.pdf |publisher=Newfoundland Labrador Department of Environment and Conservation |last=Hearn |first=Brian |date=20 February 2012 |access-date=3 February 2013 |page=7 |archive-url=https://web.archive.org/web/20160304200851/http://www.env.gov.nl.ca/env/wildlife/endangeredspecies/ssac/arctic_hare.pdf |archive-date=4 March 2016 |url-status=dead }}</ref>
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.<ref>{{Cite news |url=https://www.bbc.co.uk/news/technology-14788009 |journal=BBC News |title=Tanks test infrared invisibility cloak |date=5 September 2011 |access-date=13 June 2012}}</ref><ref name=Adaptiv-Cloak>{{cite web |url=http://www.baesystems.com/en/feature/adativ-cloak-of-invisibility |title=Adaptiv – A Cloak of Invisibility |publisher=BAE Systems |year=2011 |access-date=14 November 2015}}</ref><ref>{{cite web |url=http://www.baesystems.com/en/feature/adativ-cloak-of-invisibility#! |title=Innovation Adaptiv Car Signature |publisher=BAE Systems |year=2012 |access-date=14 November 2015}}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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.
</gallery>
===Countershading===
{{Main|Countershading}}
[[File:Countershading.svg|thumb|Countershading acts as a form of camouflage by 'painting out' the self-shadowing of the body or object. The result is a 'flat' appearance, instead of the 'solid' appearance of the body before 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.{{sfn|Cott|1940|pages=35–46}} 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''.{{sfn|Forbes|2009|pages=72–73}} Countershading is widely used by [[terrestrial animals]], such as [[gazelle]]s<ref name=Kiltie>{{cite journal |last=Kiltie |first=Richard A. |title=Countershading: Universally deceptive or deceptively universal? |journal=Trends in Ecology & Evolution |date=January 1998 |volume=3 |issue=1 |pages=21–23 |doi=10.1016/0169-5347(88)90079-1 |pmid=21227055 }}</ref> and grasshoppers; marine animals, such as [[sharks]] and [[Delphinus delphis|dolphins]];{{sfn|Cott|1940|page=41}} and birds, such as [[common snipe|snipe]] and [[dunlin]].<ref>{{cite web |url=http://www.stanford.edu/group/stanfordbirds/text/essays/Color_of_Birds.html |title=The Color of Birds |publisher=Stanford University |year=1988 |access-date=1 February 2013 |author1=Ehrlich, Paul R. |author1-link=Paul R. Ehrlich |author2=Dobkin, David S. |author3=Wheye, Darryl}}</ref>{{sfn|Cott|1940|page=40}}
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.{{sfn|Forbes|2009|pages=146–150}} 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.{{sfn|Forbes|2009|page=152}}{{sfn|Barkas|1952|page=36}} At the same time in [[Australia]], zoologist [[William John Dakin]] advised soldiers to copy animals' methods, using their instincts for wartime camouflage.{{sfn|Elias|2011|pages=57–66}}
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.<ref name=Kiltie/>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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]]
</gallery>
===Counter-illumination===
{{Main|Counter-illumination}}
[[File:Squid Counterillumination.png|thumb|Principle of [[counter-illumination]] in the [[Watasenia scintillans|firefly squid]]]]
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]], 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.<ref name="Abralia with photo">{{cite web |url=http://ocean.si.edu/ocean-photos/midwater-squid-abralia-veranyi |title=Midwater Squid, Abralia veranyi |publisher=Smithsonian National Museum of Natural History |access-date=28 November 2011}}</ref> Counterillumination camouflage is the likely function of the [[bioluminescence]] of many marine organisms, though light is also produced to attract<ref>{{cite journal |last=Young |first=Richard Edward |title=Oceanic Bioluminescence: an Overview of General Functions |journal=Bulletin of Marine Science |date=October 1983 |volume=33 |issue=4 |pages=829–845 |url=http://www.ingentaconnect.com/content/umrsmas/bullmar/1983/00000033/00000004/art00003}}</ref> or to detect prey<ref>{{cite journal |last1=Douglas |first1=R. H. |last2=Mullineaux |first2=C. W. |last3=Partridge |first3=J. C. |title=Long-wave sensitivity in deep-sea stomiid dragonfish with far-red bioluminescence: evidence for a dietary origin of the chlorophyll-derived retinal photosensitizer of Malacosteus niger |journal=Philosophical Transactions of the Royal Society B |date=September 2000 |volume=355 |issue=1401 |pages=1269–1272 |pmc=1692851 |doi=10.1098/rstb.2000.0681 |pmid=11079412}}</ref> 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.<ref name="NavalMuseumQuebec">{{cite web |title=Diffused Lighting and its use in the Chaleur Bay |url=http://www.navy.forces.gc.ca/navres/NMQ_MNQ/researches_recherches/diffusedLighting_camouflageLumineux/index-eng.asp |access-date=3 February 2013 |work=Naval Museum of Quebec |publisher=Royal Canadian Navy |archive-url=https://web.archive.org/web/20130522231113/http://www.navy.forces.gc.ca/navres/NMQ_MNQ/researches_recherches/diffusedLighting_camouflageLumineux/index-eng.asp |archive-date=22 May 2013}}</ref> 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]].<ref name="Hambling">{{cite magazine |last=Hambling |first=David |title=Cloak of Light Makes Drone Invisible? |magazine=Wired |date=9 May 2008 |url=https://www.wired.com/dangerroom/2008/05/invisible-drone |access-date=17 June 2012}}</ref> The planes were fitted with forward-pointing lamps automatically adjusted to match the brightness of the night sky.<ref name="NavalMuseumQuebec"/> This enabled them to approach much closer to a target – within {{Convert|3000|yards}} – before being seen.<ref name="Hambling"/> Counterillumination was made obsolete by [[radar]], and neither diffused lighting camouflage nor Yehudi lights entered active service.<ref name="NavalMuseumQuebec"/>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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.
</gallery>
===Transparency===
{{Further|Underwater camouflage}}
[[File:Expl0469 - Flickr - NOAA Photo Library.jpg|thumb|upright|left|Many animals of the open sea, like this ''[[Aurelia labiata]]'' jellyfish, are largely transparent.]]
Many [[Sea|marine]] animals that float near the surface are highly [[Transparency and translucency|transparent]], giving them almost perfect camouflage.{{sfn|Herring|2002|pages=190–191}} 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.{{sfn|Herring|2002|pages=190–191}} Gelatinous [[plankton]]ic 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 {{convert|650|m|ft}}; 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.{{sfn|Herring|2002|pages=190–191}}
[[File:Hyalinobatrachium uranoscopum01a.jpg|thumb|upright|[[Glass frogs]] like ''[[Hyalinobatrachium uranoscopum]]'' use partial transparency for camouflage in the dim light of the rainforest.]]
Some tissues such as [[muscle]]s 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]].{{sfn|Herring|2002|pages=190–191}} Other structures cannot be made transparent, notably the [[retina]]s 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.{{sfn|Herring|2002|pages=190–191}} Finally, some structures are visible for a reason, such as to lure prey. For example, the [[nematocyst]]s (stinging cells) of the transparent [[siphonophore]] ''[[Agalma okenii]]'' resemble small [[copepod]]s.{{sfn|Herring|2002|pages=190–191}} Examples of transparent marine animals include a wide variety of [[larva]]e, including [[radiata]] (coelenterates), siphonophores, [[salps]] (floating [[tunicate]]s), [[gastropoda|gastropod molluscs]], [[polychaete]] worms, many shrimplike [[crustacean]]s, and fish; whereas the adults of most of these are opaque and pigmented, resembling the seabed or shores where they live.{{sfn|Herring|2002|pages=190–191}}{{sfn|Cott|1940|page=6}} 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.{{sfn|Cott|1940|page=6}} 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.<ref>{{cite journal |title=The almost invisible league: crypsis and association between minute fishes and shrimps as a possible defence against visually hunting predators |author1=Carvalho, Lucélia Nobre |author2=Zuanon, Jansen |author3=Sazima, Ivan |journal=Neotropical Ichthyology |date=April–June 2006 |volume=4 |issue=2 |pages=219–224 |doi=10.1590/S1679-62252006000200008|doi-access=free }}</ref>
===Silvering===
[[File:Herringadultkils2.jpg|thumb|left|upright=1.15|The adult herring, ''[[Clupea harengus]]'', is a typical silvered fish of medium depths, camouflaged by reflection.]]
[[File:Herring Silvering.jpg|thumb|upright=0.7|The herring's reflectors are nearly vertical for camouflage from the side.]]
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.{{sfn|Herring|2002|pages=192–195}}
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 {{frac|1|4}} 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.{{sfn|Herring|2002|pages=192–195}}
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.{{sfn|Herring|2002|pages=192–195}} 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.{{sfn|Herring|2002|pages=192–195}}
===Ultra-blackness===
{{Further|Underwater camouflage}}
[[File:Humpback anglerfish.png|thumb|[[Humpback anglerfish|Blackdevil anglerfish]] is one of several deep-sea fishes camouflaged against very dark water with a black dermis.]]
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&nbsp;nm wavelength light. The ultra-blackness is achieved with a thin but continuous layer of particles in the [[dermis]], [[melanosome]]s. 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]] has driven the [[convergent evolution]] of ultra-blackness camouflage independently many times.<ref name="Davis Thomas 2020">{{cite journal |last1=Davis |first1=Alexander L. |last2=Thomas |first2=Kate N. |last3=Goetz |first3=Freya E. |last4=Robison |first4=Bruce H. |last5=Johnsen |first5=Sönke |last6=Osborn |first6=Karen J. |display-authors=3 |title=Ultra-black Camouflage in Deep-Sea Fishes |journal=Current Biology |year=2020 |volume=30 |issue=17 |pages=3470–3476.e3 |issn=0960-9822 |doi=10.1016/j.cub.2020.06.044 |pmid=32679102 |doi-access=free |bibcode=2020CBio...30E3470D }}</ref>
=== Mimesis ===
{{Further|Mimicry|Cryptic aggressive mimicry}}
In [[Mimesis (biology)|mimesis]] (also called ''masquerade''), the camouflaged object looks like something else which is of no special interest to the observer.<ref name="Gullan">{{cite book |last1=Gullan |first1=P. J. |last2=Cranston |first2=P. S. |title=The Insects |publisher=John Wiley, Blackwell |year=2010 |edition=4th |pages=512–513 |isbn=978-1-4443-3036-6 |url=https://books.google.com/books?id=S7yGZasJ7nEC&pg=PA512}}</ref> Mimesis is common in [[prey]] animals, for example when a [[peppered moth]] caterpillar mimics a twig, or a grasshopper mimics a dry leaf.{{sfn|Forbes|2009|page=151}} 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.<ref>{{Cite book |title=The Social Biology of Wasps |last=Ross |first=Kenneth G. |publisher=Cornell Press |year=1991 |isbn=978-0-801-49906-7 |page=233}}</ref>
Mimesis is also employed by some [[predation|predators]] and [[parasite]]s to lure their prey. For example, a [[flower mantis]] mimics a particular kind of flower, such as an [[orchid]].{{sfn|Forbes|2009|page=134}} This tactic has occasionally been used in warfare, for example with heavily armed [[Q-ship]]s disguised as merchant ships.<ref name="Beyer">{{cite book |last=Beyer |first=Kenneth M. |year=1999 |title=Q-Ships versus U-Boats: America's Secret Project |publisher=Naval Institute Press |isbn=978-1-55750-044-1}}</ref><ref>{{cite web |last=McMullen |first=Chris |url=http://www.gwpda.org/naval/rnqships.htm |title=Royal Navy 'Q' Ships |work=Great War Primary Documents Archive |access-date=6 March 2012 |year=2001}}</ref>{{sfn|Forbes|2009|pages=6–42}}
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.<ref>{{cite journal |doi=10.1093/beheco/arr008 |last1=Welbergen |first1=J |last2=Davies |first2=N. B. |year=2011 |title=A parasite in wolf's clothing: hawk mimicry reduces mobbing of cuckoos by hosts |journal=Behavioral Ecology |volume=22 |issue=3 |pages=574–579|doi-access=free }}</ref> The cuckoo's egg itself mimics the eggs of the host species, reducing its chance of being rejected.<ref>{{cite news |title=Cuckoo in egg pattern 'arms race' |first=Emma |last=Brennand |work=BBC News |url=http://news.bbc.co.uk/earth/hi/earth_news/newsid_9418000/9418131.stm |access-date=22 August 2011 |date=24 March 2011}}</ref><ref name="ibis2002">{{cite journal |last=Moskát |first=C |author2=Honza, M. |year=2002 |title=European Cuckoo Cuculus canorus parasitism and host's rejection behaviour in a heavily parasitized Great Reed Warbler Acrocephalus arundinaceus population |journal= Ibis |doi=10.1046/j.1474-919X.2002.00085.x |volume= 144 |issue=4 |pages=614–622}}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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
</gallery>
===Motion dazzle===
{{Distinguish|dazzle camouflage}}
[[File:Chapman-Zebra.jpg|thumb|upright|The [[zebra]]'s bold pattern may induce motion dazzle in observers]]
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.<ref name=Scott-Samuel/> Motion dazzle may degrade predators' ability to estimate the prey's speed and direction accurately, giving the prey an improved chance of escape.<ref name=StevensMotionDazzle>{{Cite journal |journal=BMC Biology |volume=9 |pages=9–81 |doi=10.1186/1741-7007-9-81 |pmid=22117898 |pmc=3257203 |title=Motion dazzle and camouflage as distinct anti-predator defenses |date=25 November 2011 |author1=Stevens, Martin |author1-link=Martin Stevens (biologist) |author2=Searle, W. T. L. |author3=Seymour, J. E. |author4=Marshall, K. L. A. |author5=Ruxton, Graeme D. |author5-link=Graeme Ruxton |doi-access=free }}</ref> 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<!-- NOT THE SAME as "Dazzle Camouflage" --> had been proposed for military vehicles, but never applied.<ref name=Scott-Samuel>{{cite journal |title=Dazzle Camouflage Affects Speed Perception |author1=Scott-Samuel, N. E. |author2=Baddeley, R. |author3=Palmer, C. E. |author4=Cuthill, Innes C. |author4-link=Innes Cuthill |journal=PLOS ONE |date=June 2011 |volume=6 |issue=6 |doi=10.1371/journal.pone.0020233 |editor1-last=Burr |editor1-first=David C. |page=e20233 |pmid=21673797 |pmc=3105982|bibcode=2011PLoSO...620233S |doi-access=free }}</ref> Since motion dazzle patterns<!--this is not WWI-style "dazzle painting"--> 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.<ref name=StevensMotionDazzle/>
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,{{sfn|Cott|1940|page=94}} background-blending and countershading.{{sfn|Thayer|1909|page=136}}{{efn|The belly of the zebra is white, and the dark stripes narrow towards the belly, so the animal is certainly countershaded, but this does not prove that the main function of the stripes is camouflage.}} After many years in which the purpose of the coloration was disputed,<ref>{{cite journal |title=Contrasting coloration in terrestrial mammals |last=Caro |first=Tim |author-link=Tim Caro |journal=Philosophical Transactions of the Royal Society B |year=2009 |volume=364 |pages=537–548 |doi=10.1098/rstb.2008.0221 |pmc=2674080 |issue=1516 |pmid=18990666}}</ref> 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]].<ref>{{cite journal |last=Waage |first=J. K. |year=1981 |title=How the zebra got its stripes: biting flies as selective agents in the evolution of zebra colouration |journal=J. Entom. Soc. South Africa |volume=44 |pages=351–358}}</ref><ref>{{cite journal |title=Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes |last1=Egri |first1=Ádám |last2=Blahó |first2=Miklós |last3=Kriska |first3=György  |author4=Farkas, Róbert |author5=Gyurkovszky, Mónika |author6=Åkesson, Susanne  |author7=Horváth, Gábor |display-authors=3 |journal=The Journal of Experimental Biology |date=March 2012 |volume=215 |pages=736–745 |doi=10.1242/jeb.065540 |issue=5 |pmid=22323196|doi-access=free }}</ref> 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 illusion]]s: the [[wagon-wheel effect]], where the perceived motion is inverted, and the [[barberpole illusion]], where the perceived motion is in a wrong direction.<ref>{{cite journal |url=https://espace.library.uq.edu.au/view/UQ:319813/UQ319813.pdf|title=Motion camouflage induced by zebra stripes |last1=How |first1=Martin J. |last2=Zanker |first2=Johannes M. |journal=Zoology |year=2014 |pages=163–170 |doi=10.1016/j.zool.2013.10.004 |pmid=24368147 |volume=117|issue=3 |bibcode=2014Zool..117..163H }}</ref>
==Applications==
===Military===
{{Main|Military camouflage|List of military clothing camouflage patterns}}
====Before 1800====
[[File:Museum für Antike Schifffahrt, Mainz 02. Spritsail.jpg|thumb|Roman ships, depicted on a 3rd-century AD [[sarcophagus]]]]
Ship camouflage was occasionally used in ancient times. [[Philostratus]] ({{Circa|172–250 AD}}) wrote in his ''[[Imagines (work by Philostratus)|Imagines]]'' that Mediterranean pirate ships could be painted blue-gray for concealment.{{sfn|Casson|1995|pages=211–212}} [[Publius Flavius Vegetius Renatus|Vegetius]] ({{circa|360–400&nbsp;AD}}) 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.{{sfn|Casson|1995|page=235}} 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&nbsp;AD, hunting birds with blowpipes which are fitted with a kind of shield near the mouth, perhaps to conceal the hunters' hands and faces.<ref>{{cite journal |last=Jett |first=Stephen C. |date=March 1991 |title=Further Information on the Geography of the Blowgun and Its Implications for Early Transoceanic Contacts |journal=Annals of the Association of American Geographers |volume=81 |issue=1 |pages=89–102 |jstor=2563673 |doi=10.1111/j.1467-8306.1991.tb01681.x}}</ref> 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.<ref>{{cite book |title=The Crossbow |url=https://archive.org/details/TheCrossbowMediaevalAndModern |publisher=Longmans, Green |last=Payne-Gallwey |first=Ralph |year=1903 |page=[https://archive.org/details/TheCrossbowMediaevalAndModern/page/n43 11]}}</ref> [[Jamaican Maroons]] are said to have used plant materials as camouflage in the [[First Maroon War]] ({{circa|1655–1740}}).<ref>{{cite book |last=Saunders |first=Nicholas |title=The People of the Caribbean: An Encyclopedia of Archaeology and Traditional Culture |year=2005 |publisher=ABC-CLIO}}</ref>
====19th-century origins====
[[File:Green jacketed rifleman firing Baker rifle 1803.jpg|thumb|upright|[[Rifle Brigade (Prince Consort's Own)|Green-jacketed rifleman]] firing [[Baker rifle]] 1803]]
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]] 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.<ref>{{cite book |last=Haythornthwaite |first=P. |title=British Rifleman 1797–1815 |publisher=Osprey Publishing |year=2002 |page=20 |isbn=978-1841761770}}</ref> 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.{{sfn|Newark|2007|page=43}}
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.<ref>{{cite web |url=http://www.historynet.com/killers-in-green-coats.htm |title=Killers in Green Coats |publisher=Weider History Group |date=20 February 2008 |access-date=8 July 2012}}</ref> 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.<ref>{{cite journal |title=Khaki Uniform 1848–49: First Introduction by Lumsden and Hodson |journal=Journal of the Society for Army Historical Research |year=2004 |volume=82 |issue=Winter |pages=341–347}}</ref> Hodson wrote that it would be more appropriate for the hot climate, and help make his troops "invisible in a land of dust".<ref>{{cite book |title=Twelve Years of a Soldier's Life in India, being extracts from the letters of the late Major WSR Hodson |publisher=John W. Parker and Son |last=Hodson |first=W. S. R. |editor=Hodson, George H. |year=1859 |url=http://babel.hathitrust.org/cgi/pt?id=uc2.ark:/13960/t14m94h66;view=1up;seq=9}}</ref> 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;<ref>{{cite book |last=Barthorp |first=Michael |title=The British Army on Campaign 1816–1902 |volume=4 |issue=1882–1902 |publisher=Osprey Publishing |year= 1988 |isbn=978-0-85045-849-7 |pages=24–33}}</ref> by the [[Second Boer War]] six years later it was used throughout the British Army.<ref>{{cite book |last=Chappell |first=M. |title=The British Army in World War I (1) |publisher=Osprey Publishing |year=2003 |page=37 |isbn=978-1-84176-399-6}}</ref>
During the late 19th century camouflage was applied to British coastal fortifications.<ref>{{cite journal |last1=Barrass |first1=S |date=2018 |title=British Military Camouflage Prior to 1914 |journal=Casemate |issue=111 |pages=34–42 |publisher=[[Fortress Study Group]] |issn=1367-5907 }}</ref> The fortifications around Plymouth, England were painted in the late 1880s in "irregular patches of red, brown, yellow and green."<ref>{{cite book |last=Lewis |first=JF |date=1890 |title=Permanent Fortification for English Engineers |publisher=The Royal Engineers Institute |page=280 }}</ref> From 1891 onwards British coastal artillery was permitted to be painted in suitable colours "to harmonise with the surroundings"<ref>{{cite book |author=<!--Staff writer(s); no by-line.--> |title=Details of Equipment of Her Majesty's Army Part 2 Section XI B – Garrison Artillery |publisher=War Office |date=1891 }}</ref> 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."<ref>{{cite book |author=<!--Staff writer(s); no by-line.--> |title=Regulations for the equipment of the army. Part 2. section XII (a) |publisher=War Office |date=1904 }}</ref>
====First World War====
{{Further|list of camoufleurs}}
[[File:Andre Mare Camouflaged Iron Observation Tree (The Elm at Vermezeele) 1916.jpg|thumb|upright|Iron observation post camouflaged as a tree by [[Cubism|Cubist]] painter [[André Mare]], 1916]]
In the [[First World War]], the French army formed a camouflage corps, led by [[Lucien-Victor Guirand de Scévola]],<ref name=LRB>{{cite journal |url=http://www.lrb.co.uk/v27/n12/patrick-wright/cubist-slugs |title=Cubist Slugs |last=Wright |first=Patrick |journal=[[London Review of Books]] |date=23 June 2005 |volume=27 |issue=12 |pages=16–20}}</ref><ref>{{cite journal |last=Guirand de Scévola |first=Lucien-Victor |title=Souvenir de Camouflage (1914–1918) |journal=Revue des Deux Mondes |date=December 1949 |language=fr |author-link=Lucien-Victor Guirand de Scévola}}</ref> 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.{{sfn|Forbes|2009|pages=104–105}}<ref>{{cite web |title=Art of the First World War: André Mare and Leon Underwood |work=The Elm at Vermezeele |publisher=Memorial-Caen |year=1998 |url=http://www.memorial-caen.fr/10EVENT/EXPO1418/gb/texte/027text.html |access-date=8 February 2013 |archive-url=https://web.archive.org/web/20130529001851/http://www.memorial-caen.fr/10EVENT/EXPO1418/gb/texte/027text.html |archive-date=29 May 2013 |url-status=dead }}</ref><ref>{{cite web |title=Art of the First World War: André Mare |publisher=Memorial-Caen |year=1998 |url=http://www.memorial-caen.fr/10EVENT/EXPO1418/gb/texte/008text.html |access-date=8 February 2013 |archive-url=https://web.archive.org/web/20130528220115/http://www.memorial-caen.fr/10EVENT/EXPO1418/gb/texte/008text.html |archive-date=28 May 2013 |url-status=dead }}</ref> The term ''[[wikt:camouflage|camouflage]]'' probably comes from ''camoufler'', a [[Paris]]ian slang term meaning ''to disguise'', and may have been influenced by ''camouflet'', a [[French language|French]] term meaning ''smoke blown in someone's face''.<ref name=camouflet>{{cite web |title=Camouflage |work=Online Etymology Dictionary |year=2012 |url=http://etymonline.com/index.php?term=camouflage&allowed_in_frame=0 |access-date=8 February 2013}}</ref><ref>{{cite web |title=Camouflage, n |work=Oxford English Dictionary |publisher=Oxford University Press |url=http://www.oed.com/view/Entry/26737?isAdvanced=false&result=1&rskey=2NawDO&|access-date=8 February 2013}}</ref> 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.{{sfn|Forbes|2009|pages=85–89}}<ref>For Solomon, see BBC Radio 4 programme "Warpaint: the story of camouflage" by Patrick Wright, August 2002 (repeated Radio 4 Extra, 17 June 2014).</ref> 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.<ref>{{cite book |title=Camouflage and Art Design for Deception in World War 2 |last=Goodden |first=Henrietta |publisher=Unicorn Press |year=2007 |isbn=978-0-906290-87-3 |location=London, England |pages=12–13}}</ref>
[[Ship camouflage]] was introduced in the early 20th century as the range of naval guns increased, with ships painted grey all over.<ref name=Sumrall/><ref>{{cite web |last=Prinzeugen |title=Schnellboot: An Illustrated Technical History |work=Prinz Eugen |url=http://www.prinzeugen.com/colors.htm |access-date=5 March 2012 |archive-date=19 September 2016 |archive-url=https://web.archive.org/web/20160919134326/http://www.prinzeugen.com/colors.htm |url-status=dead }}</ref> 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.<ref>{{cite news |work=The Times |title=Obituary: Mr Norman Wilkinson, Inventor of 'dazzle' painting |date=1 June 1971 |page=12}}</ref> 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".<ref>{{cite book |last=Wilkinson |first=Norman |author-link=Norman Wilkinson (artist) |title=A Brush with Life |publisher=Seeley Service |year=1969 |page=79}}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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
</gallery>
====Second World War====
{{Further|list of camoufleurs|World War II ship camouflage measures of the United States Navy|German World War II camouflage patterns}}
In the [[Second World War]], 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.{{sfn|Forbes|2009|pages=149–150}} 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.<ref>{{cite web |last=Keating |first=Kenneth C. |url=http://apps.dtic.mil/dtic/tr/fulltext/u2/a112903.pdf |archive-url=https://web.archive.org/web/20140519040222/http://www.dtic.mil/dtic/tr/fulltext/u2/a112903.pdf |url-status=live |archive-date=19 May 2014 |title=Maskirovka: The Soviet System of Camouflage |publisher=U.S. Army Russian Institute |year=1981 |access-date=8 July 2012}}</ref> 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.<ref>{{cite book |title=Kursk: the greatest battle |publisher=Headline Review |last=Clark |first=Lloyd |year=2011 |page=278 |isbn=978-0-7553-3639-5}}</ref> 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.<ref>{{cite book |last=Shaw |first=Robert L. |title=Fighter Combat: Tactics and Maneuvering |year=1985 |publisher=Naval Institute Press |isbn=978-0-87021-059-4 |url=https://archive.org/details/fightercombattac00shaw }}</ref> Bombers and night fighters were often black,<ref>Stephenson, Hubert Kirk (1948). ''Applied Physics'', pp. 200, 258. Volume 6 of Science in World War II; Office of Scientific Research and Development. Editors: Chauncey Guy Suits and George Russell Harrison. Little, Brown.</ref> while maritime reconnaissance planes were usually white, to avoid appearing as dark shapes against the sky.<ref>{{cite book |last=Tinbergen |first=Niko |author-link=Niko Tinbergen |title=The Herring Gull's World |publisher=Collins |year=1953 |page=14 |isbn=978-0-00-219444-0 |quote=white has proved to be the most efficient concealing coloration for aircraft on anti-submarine patrol}}</ref> For ships, dazzle camouflage was mainly replaced with plain grey in the Second World War, though experimentation with colour schemes continued.<ref name=Sumrall/>
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]],<ref>{{cite web |url= http://www.farnhamcastle.com/index.php?option=com_content&view=article&id=79&Itemid=133 |work=Farnham Castle |title=World War II|access-date=8 February 2013}}</ref> writing the practical ''Home Guard Manual of Camouflage''.{{sfn|Forbes|2009|pages =151–152}} 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]].{{sfn|Barkas|1952|pages=154, 186–188}}{{sfn|Forbes|2009|pages=156–166}} 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.<ref>{{cite book |last=Mellor |first=D. P. |series=Australia in the War of 1939–1945. Series 4 – Civil |volume=5 |title=The Role of Science and Industry |publisher=Australian War Memorial |location=Canberra |year=1958 |page=538ff}}</ref> 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.<ref>{{cite book |last=Shapiro |first=Danielle |title=John Vassos: Industrial Design for Modern Life |publisher=University of Minnesota Press |year=2016 |isbn=978-0-8166-9341-2 |page=183}}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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:Mitchell 180 Sqn RAF in especially camouflaged hangar Belgium 1944.jpg-->
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
</gallery>
====After 1945====
{{Further|List of camouflage patterns}}
Camouflage has been used to protect military equipment such as vehicles, guns, [[Ship camouflage|ships]],<ref name=Sumrall>{{cite journal |last=Sumrall |first=R. F. |title=Ship Camouflage (WWII): Deceptive Art |journal=United States Naval Institute Proceedings |date=February 1973 |pages=67–81}}</ref> [[Aircraft camouflage|aircraft]] and buildings<ref>{{cite magazine |url=http://www.smithsonianconference.org/climate/wp-content/uploads/2009/09/ConcealmentCamouflageDeception.pdf |archive-url=https://web.archive.org/web/20130614033015/http://www.smithsonianconference.org/climate/wp-content/uploads/2009/09/ConcealmentCamouflageDeception.pdf |archive-date=2013-06-14 |url-status=live |title=Concealment, Camouflage, and Deception |magazine=Smithsonian |access-date=16 June 2012 |pages=1–4}}</ref> as well as individual soldiers and their positions.<ref>{{cite web |url=https://irp.fas.org/doddir/army/fm3-21-75.pdf|title=FM 21–75 |archive-url=https://web.archive.org/web/20210926093542/https://irp.fas.org/doddir/army/fm3-21-75.pdf| archive-date=26 September 2021|work=Chapter 5: Cover, Concealment, and Camouflage |access-date=11 June 2023 |publisher=Department of the Army}}</ref>
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.<ref>{{cite web |url=http://library.enlistment.us/field-manuals/series-2/FM21_305/TOC.PDF |archive-url=https://web.archive.org/web/20151117031813/http://library.enlistment.us/field-manuals/series-2/FM21_305/TOC.PDF |archive-date=2015-11-17 |url-status=live |title=FM 21-305/AFMAN 24-306 |work=Chapter 20: Vehicle Camouflage And Nuclear, Biological, And Chemical Operations |access-date=16 June 2012 |pages=1–9 |publisher=Department of the Army}}</ref><ref>{{cite web |url=https://archive.org/details/milmanual-fm-5-103-survivability |title=5–103 |work=Appendix D: Camouflage |access-date=17 June 2012 |publisher=Department of the Army}}</ref><ref>{{cite web |url=http://www.armedforces-int.com/suppliers/multispectral-camouflage.html |title=SSZ Camouflage |publisher=Military Suppliers & News |year=2012 |access-date=17 June 2012}}</ref> Some military textiles and vehicle camouflage paints also reflect infrared to help provide concealment from [[image intensification|night vision]] devices.<ref>{{cite journal |title=Color Stability of Olive Drab Infrared-Reflecting Camouflage Finishes |author1=Jukkola, E. E. |author2=Cohen, R. |journal=Industrial & Engineering Chemistry |year=1946 |volume=38 |issue=9 |pages=927–930 |doi=10.1021/ie50441a019}}</ref>
After the Second World War, radar made camouflage generally less effective, though coastal boats are sometimes painted like land vehicles.<ref name=Sumrall/> [[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.<ref>{{cite book |last=Richardson |first=Doug |title=Stealth Warplanes: Deception, Evasion, and Concealment in the Air |publisher=MBI Publishing, Zenith Press |year=2001 |url=https://www.scribd.com/doc/118487425/Stealth-Warplanes |isbn=978-0-7603-1051-9 |access-date=9 September 2017 |archive-date=7 April 2015 |archive-url=https://web.archive.org/web/20150407064050/https://www.scribd.com/doc/118487425/Stealth-Warplanes |url-status=dead }}</ref>
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).<ref>{{cite journal |url=http://www.icrc.org/eng/assets/files/other/irrc_853_pfanner.pdf |archive-url=https://web.archive.org/web/20110813082353/http://www.icrc.org/eng/assets/files/other/irrc_853_pfanner.pdf |archive-date=2011-08-13 |url-status=live |title=Military uniforms and the law of war |last=Pfanner |first=Toni |journal=IRRC |date=March 2004 |volume=86 |issue=853 |pages=99–100 |doi=10.1017/s1560775500180113|s2cid=144589400 }}</ref> The design of a pattern effective in all terrains has proved elusive.<ref name=US-Army>{{cite book |title=FM 21–76 US Army Survival Manual |publisher= Department of the Army |url=https://archive.org/details/Fm21-76SurvivalManual |access-date=8 January 2013}}</ref><ref>{{cite book |title=Photosimulation Camouflage Detection Test |year=2009 |publisher=U.S. Army Natick Soldier Research, Development and Engineering Center |page=27 |url=https://www.scribd.com/doc/19823845/Photosimulation-Camouflage-Detection-Test|access-date=5 October 2012}}</ref><ref name=Brayley>{{cite book |last=Brayley |first=Martin J |title=Camouflage uniforms: international combat dress 1940–2010 |year=2009 |publisher=Crowood |isbn=978-1-84797-137-1}}</ref> The American [[Universal Camouflage Pattern]] of 2004 attempted to suit all environments, but was withdrawn after a few years of service.<ref>{{cite news |last=Freedberg |first=S. J. Jr. |title=Army drops universal camouflage after spending billions |url=http://defense.aol.com/2012/06/25/army-drops-universal-camouflage-after-spending-billions |access-date=27 September 2012 |newspaper=AOL Defence |date=25 June 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120831104046/http://defense.aol.com/2012/06/25/army-drops-universal-camouflage-after-spending-billions/ |archive-date=31 August 2012}}</ref> Terrain-specific patterns have sometimes been developed but are ineffective in other terrains.<ref>{{cite web |last=Davies |first=W. |title=Berlin Brigade Urban Paint Scheme |url=http://www.emlra.org/index.php/articles/berlin-brigade-urban-paint-scheme |work=Newsletter |publisher=Ex-Military Land Rover Association |access-date=25 September 2012 |archive-url=https://web.archive.org/web/20130312155920/http://www.emlra.org/index.php/articles/berlin-brigade-urban-paint-scheme |archive-date=12 March 2013 |url-status=dead }}</ref> 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.<ref>{{cite web |last=Craemer |first=Guy |title=Dual Texture – U.S. Army digital camouflage |url=http://www.uniteddynamics.com/dualtex |publisher=United Dynamics |access-date=27 September 2012}}</ref> 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.<ref>{{cite news |last=Engber |first=D. |title=Lost in the Wilderness, the military's misadventures in pixellated camouflage |orig-year=2007 |work=[[Slate (magazine)|Slate]] |url=http://www.slate.com/articles/health_and_science/science/2012/07/camouflage_problems_in_the_army_the_ucp_and_the_future_of_digital_camo_.single.html |access-date=27 September 2012 |date=5 July 2012}}</ref>
<gallery class="center" mode="nolines" heights="150px" widths="150px">
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 Chinese [[People's Liberation Army]] [[Type 99 (camouflage)|Type 99]] pattern, {{Circa|2006}}<!--date of photo; [http://camopedia.org/index.php?title=China Camopedia says "around 1999"]-->
File:Flecktarn.jpg|Modern German [[Flecktarn]] 1990, developed from a 1938 pattern, a non-digital pattern which works at different distances
File:Six-Color Desert Pattern.jpg|US "Chocolate Chip" [[Six-Color Desert Pattern]] developed in 1962, widely used in [[Gulf War]]
</gallery>
===Hunting===
[[File:Deer blind.jpg|thumb|upright|left|A [[hunting blind|hide]] used in [[field sports]]]]
Hunters of game have long made use of camouflage in the form of materials such as animal skins, mud, foliage, and green or brown clothing to enable them to approach wary game animals.{{sfn|Newark|2007|page=38}} [[Field sports]] such as [[driven grouse shooting]] conceal hunters in [[hunting blind|hides]] (also called blinds or shooting butts).<ref name=Blakeley2012>{{cite book |last=Blakeley |first=Peter F. |title=Wingshooting |publisher=Stackpole Books |year=2012 |pages=116, 125 |isbn=978-0-8117-0566-0}}</ref> Modern hunting clothing makes use of fabrics that provide a disruptive camouflage pattern; for example, in 1986 the hunter Bill Jordan created cryptic clothing for hunters, printed with images of specific kinds of vegetation such as grass and branches.{{sfn|Newark|2007|pages=48, 50}}
===Civil structures===
[[File:Camouflaged Microwave Cell Telephone Tower.JPG|thumb|right|upright=0.6|Cellphone tower disguised as a tree]]
Camouflage is occasionally used to make built structures less conspicuous: for example, in [[South Africa]], towers carrying cell telephone antennae are sometimes camouflaged as tall trees with plastic branches, in response to "resistance from the community". Since this method is costly (a figure of three times the normal cost is mentioned), alternative forms of camouflage can include using neutral colours or familiar shapes such as cylinders and flagpoles. Conspicuousness can also be reduced by siting masts near, or on, other structures.<ref>{{cite book |last=du Plessis |first=A. |title=Telecommunication Mast Management Guidelines for the City of Tshwane |publisher=[[City of Tshwane Metropolitan Municipality]] |date=3 July 2002 |url=http://www.tshwane.gov.za/AboutTshwane/CityManagement/CityDepartments/CorporateandSharedServices/legalservices/_layouts/mobile/view.aspx?List=1c67d863-b080-497c-b5e6-5f737c9debda&View=01d8646a-31ab-4506-a31d-76c75e245307&RootFolder=%2FAboutTshwane%2FCityManagement%2FCityDepartments%2FCorporateandSharedServices%2Flegalservices%2FPolicies%20Listing%2FTelkom%20Mast&ViewMode=Detail}}</ref>
Automotive manufacturers often use patterns to disguise upcoming products. This camouflage is designed to obfuscate the vehicle's visual lines, and is used along with padding, covers, and decals. The patterns' purpose is to prevent visual observation (and to a lesser degree photography), that would subsequently enable reproduction of the vehicle's form factors.<ref>{{cite news |title=The secrets behind all that camouflage |url=http://www.autonews.com/article/20150512/BLOG06/150519967/the-secrets-behind-all-that-camouflage |newspaper=Automotive News |access-date=28 July 2015 |date=12 May 2015}}</ref>
===Fashion, art and society===
[[File:Dazzle camouflage costume ball.PNG|thumb|The "dazzle ball" held by the Chelsea Arts Club, 1919|alt=1919 dazzle ball costumes]]
Military camouflage patterns influenced [[Fashion design|fashion]] and [[art]] from the time of the First World War onwards. [[Gertrude Stein]] recalled the [[cubism|cubist]] artist [[Pablo Picasso]]'s reaction in around 1915:
{{Blockquote|I very well remember at the beginning of the war being with Picasso on the boulevard Raspail when the first camouflaged truck passed. It was at night, we had heard of camouflage but we had not seen it and Picasso amazed looked at it and then cried out, yes it is we who made it, that is cubism.|Gertrude Stein in ''From Picasso'' (1938)<ref>{{cite web |author=[[Gertrude Stein|Stein, Gertrude]] |translator=[[Alice B. Toklas|Toklas, Alice B.]] |title=Picasso |publisher=Scribners |year=1939 |url=http://faculty.dwc.edu/wellman/Stein-Picasso.html |access-date=31 January 2014 |archive-url=https://web.archive.org/web/20140201234007/http://faculty.dwc.edu/wellman/Stein-Picasso.html |archive-date=1 February 2014 |url-status=dead}}</ref>}}
In 1919, the attendants of a "dazzle ball", hosted by the Chelsea Arts Club, wore dazzle-patterned black and white clothing. The ball influenced fashion and art via postcards and magazine articles.{{sfn|Forbes|2009|page=100}} The ''[[Illustrated London News]]'' announced:{{sfn|Forbes|2009|page=100}}<ref>{{cite news |work=Illustrated London News |title=The Great Dazzle Ball at the Albert Hall: The Shower of Bomb Balloons and Some Typical Costumes |date=22 March 1919 |issue=154 |pages=414–415}}</ref>
{{Blockquote|The scheme of decoration for the great fancy dress ball given by the Chelsea Arts Club at the Albert Hall, the other day, was based on the principles of "Dazzle", the method of "camouflage" used during the war in the painting of ships&nbsp;... The total effect was brilliant and fantastic.}}
More recently, fashion designers have often used camouflage fabric for its striking designs, its "patterned disorder" and its symbolism.<ref name="Galliano at Museum">{{cite web |url=http://www3.fitnyc.edu/museum/loveandwar/galliano.htm |title=Love and War: The Weaponized Woman |publisher=The Museum at FIT |work=John Galliano for Christian Dior, silk camouflage evening dress |date=9 September – 16 December 2006 |access-date=1 December 2011 |url-status=dead |archive-url=https://archive.today/20121212085814/http://www3.fitnyc.edu/museum/loveandwar/galliano.htm |archive-date=12 December 2012}}</ref> Camouflage clothing can be worn largely for its symbolic significance rather than for fashion, as when, during the late 1960s and early 1970s in the United States, [[opposition to the Vietnam War|anti-war protestors]] often ironically wore military clothing during demonstrations against the American involvement in the Vietnam War.<ref>{{cite web |url=http://www.warmuseum.ca/media/news/the-story-of-camouflage-told-at-the-canadian-war-museum-this-summer/ |title=Camouflage: The Exhibition |publisher=Canadian War Museum |date=5 June 2009 |access-date=14 November 2015}}</ref>
Modern artists such as [[Ian Hamilton Finlay]] have used camouflage to reflect on war. His 1973 screenprint of a tank camouflaged in a leaf pattern, ''Arcadia'',{{efn|See [[Ian Hamilton Finlay#Art]].}} is described by the [[Tate gallery|Tate]] as drawing "an ironic parallel between this idea of a natural paradise and the camouflage patterns on a tank".<ref name="IanHF-Tate">{{cite web |url=http://www.tate.org.uk/art/artworks/hamilton-finlay-arcadia-collaboration-with-george-oliver-p07025 |title=Ian Hamilton Finlay: Arcadia (collaboration with George Oliver) |publisher=Tate |work=Arcadia, 1973 |date=July 2008 |access-date=11 May 2012}}</ref> The title refers to the [[Utopia]]n [[Arcadia (utopia)|Arcadia]] of poetry and art, and the ''[[memento mori]]'' [[Latin phrase]] ''Et in Arcadia ego'' which recurs in Hamilton Finlay's work. In [[science fiction]], ''[[Camouflage (novel)|Camouflage]]'' is a novel about [[shapeshifting]] alien beings by [[Joe Haldeman]].<ref>{{cite book |last=Haldeman |first=Joe |title=Camouflage |publisher=Ace Books |year=2004 |isbn=978-0-441-01161-2 |url=https://archive.org/details/camouflage00hald }}</ref> The word is used more figuratively in works of literature such as Thaisa Frank's collection of stories of love and loss, ''A Brief History of Camouflage''.<ref>{{cite book |last=Frank |first=Thaisa |title=A Brief History of Camouflage |publisher=Black Sparrow Press |year=1992 |isbn=978-0-87685-857-8 |url=https://archive.org/details/briefhistoryofca00fran }}</ref>
In 1986, [[Andy Warhol]] began a series of monumental camouflage paintings, which helped to transform camouflage into a popular print pattern. A year later, in 1987, New York designer [[Stephen Sprouse]] used Warhol's camouflage prints as the basis for his Autumn Winter 1987 collection.<ref>{{Cite web |title=Stephen Sprouse {{!}} Suit {{!}} American |url=https://www.metmuseum.org/art/collection/search/83908 |access-date=2024-07-13 |website=The Metropolitan Museum of Art |language=en}}</ref>{{clear}}
<gallery class="center" mode="nolines" heights="150px" widths="150px">
File:André_Mare_1885-1932_Camouflaged_280_Gun_sketch_in_ink_and_watercolour.jpg|[[André Mare]]'s [[Cubism|Cubist]] [[sketch (drawing)|sketch]], {{circa|1917}}, of a 280 calibre gun illustrates the interplay of art and war, as artists like Mare contributed their skills as wartime ''[[camoufleurs]]''.
File:Vietnam War protest in Washington DC April 1971.jpg|Camouflage clothing in an [[opposition to the Vietnam War|anti-war protest]], 1971
File:Aline Campos 1c.jpg|A camouflage skirt as a [[fashion]] item, 2007
</gallery>
==Notes==
{{Notelist}}
==References==
{{Reflist}}
==Bibliography==
===Camouflage in nature===
====Early research====
* {{cite book |last=Beddard |first=Frank Evers |author-link=Frank Evers Beddard |year=1892 |title=Animal Coloration |publisher=Swan Sonnenschein |title-link=Animal Coloration (book) }}
* {{cite book |last=Cott |first=Hugh B. |author-link=Hugh B. Cott |year=1940 |title=Adaptive Coloration in Animals |publisher=Methuen |title-link=Adaptive Coloration in Animals }}
* {{cite book |last=Darwin |first=Charles |author-link=Charles Darwin |year=1859 |title=On the Origin of Species  |publisher=John Murray |title-link=On the Origin of Species }} Reprinted 1985, Penguin Classics.
* {{cite book |last=Poulton |first=Edward B. |author-link=Edward Bagnall Poulton |year=1890 |title=The Colours of Animals |publisher=Kegan Paul, Trench, Trübner |title-link=The Colours of Animals }}
* {{cite book |last=Thayer |first=Abbott Handerson |author-link=Abbott Handerson Thayer |year=1909 |title=Concealing-Coloration in the Animal Kingdom Macmillan |title-link=Concealing-Coloration in the Animal Kingdom }}
====General reading====
* {{cite book |last=Elias |first=Ann |year=2011 |title=Camouflage Australia: Art, Nature, Science and War |publisher=Sydney University Press |isbn=978-1-920899-73-8 }}
*Elias, Ann (2015). ''Camouflage Cultures: Beyond the Art of Disappearance.'' Sydney University Press. {{ISBN|978-1-743324-25-7}}.
* {{cite book |last=Forbes |first=Peter |year=2009 |title=Dazzled and Deceived: Mimicry and Camouflage |publisher=Yale University Press |isbn=978-0-300-17896-8 |title-link=Dazzled and Deceived: Mimicry and Camouflage }}
* {{cite book |last=Herring |first=Peter |author-link=Peter Herring |year=2002 |title=The Biology of the Deep Ocean |publisher=Oxford University Press |isbn=978-0-19-854956-7 }}
* {{cite book |last=Rothenberg |first=David |author-link=David Rothenberg |year=2011 |title=Survival of the Beautiful: Art, Science and Evolution |publisher=Bloomsbury |isbn=978-1-60819-216-8 |url-access=registration |url=https://archive.org/details/survivalofbeauti0000roth }}
===Military camouflage===
* {{cite book |last=Barkas |first=Geoffrey |author-link=Geoffrey Barkas |year=1952 |title=The Camouflage Story (from Aintree to Alamein) |publisher=Cassell }}
* {{cite book |last=Casson |first=Lionel |author-link=Lionel Casson |year=1995 |title=Ships and Seamanship in the Ancient World |publisher=JHU Press |isbn=978-0-8018-5130-8 }}
* {{cite book |last=Newark |first=Tim |year=2007 |title=Camouflage |publisher=Thames and Hudson, with [[Imperial War Museum]] |isbn=978-0-500-51347-7 }}
==Further reading==
* [[Roy Behrens|Behrens, Roy R.]] (2002). ''False Colors: Art, Design and Modern Camouflage''. Bobolink Books. {{ISBN|0-9713244-0-9}}.
* [[Roy Behrens|Behrens, Roy R.]] (2009). ''Camoupedia: A Compendium of Research on Art, Architecture and Camouflage''. Bobolink Books. {{ISBN|978-0-9713244-6-6}}.
* [[Roy Behrens|Behrens, Roy R.]] (editor) (2012). ''Ship Shape: A Dazzle Camouflage Sourcebook''. Bobolink Books. {{ISBN|978-0-9713244-7-3}}.
* Goodden, Henrietta (2009). ''Camouflage and Art: Design for Deception in World War 2''. Unicorn Press. {{ISBN|978-0-906290-87-3}}.
* [[Jon Latimer|Latimer, Jon]] (2001). ''Deception in War''. John Murray. {{ISBN|978-1-58567-381-0}}.
* Newman, Alex; Blechman, Hardy (2004). ''DPM – Disruptive Pattern Material: An Encyclopaedia of Camouflage: Nature, Military and Culture''. DPM. {{ISBN|978-0-9543404-0-7}}.
* Shell, Hanna Rose (2012). ''Hide and Seek: Camouflage, Photography and the Media of Reconnaissance''. Zone Books. {{ISBN|978-1-935-40822-2}}.
* [[Martin Stevens (biologist)|Stevens, Martin]]; Merilaita, Sami (2011). ''Animal Camouflage: Mechanisms and Function''. Cambridge University Press. {{ISBN|978-0-521-15257-0}}.
* [[Wolfgang Wickler|Wickler, Wolfgang]] (1968). ''Mimicry in plants and animals''. McGraw-Hill. {{ISBN|978-0-07-070100-7}}.
===For children===
* Kalman, Bobbie; Crossingham, John (2001). ''What are Camouflage and Mimicry?''. Crabtree Publishing. {{ISBN|978-0-86505-962-7}}. (ages 4–8)
* Mettler, Rene (2001). ''Animal Camouflage''. First Discovery series. Moonlight Publishing. {{ISBN|978-1-85103-298-3}}. (ages 4–8)
==External links==
{{Commons category}}
{{Wiktionary|camouflage}}
* [http://camouflage.osu.edu/ Ohio State University: The Camouflage Project] – interplay of science and art
* Behrens, Roy. [http://bobolinkbooks.googlepages.com/royr.behrens A Chronology of Camouflage]
{{Camouflage}}
{{Camoufleurs}}
{{Vision in animals}}
{{Modelling ecosystems}}
{{evo ecol}}
{{Patterns in nature}}
{{Hunting topics}}
{{Authority control}}
[[Category:Camouflage| ]]
[[Category:Survival skills]]
[[Category:Deception]]
[[Category:Hunting]]
[[Category:Antipredator adaptations]]
[[Category:Biological interactions]]
[[Category:Evolutionary ecology]]