Deception Mimicry and Camouflage

Category: File - :Musee de la bible et Terre Sainte 001.JPG|thumb|This stone mask from the pre-ceramic neolithic period dates to 7000 BCE and is probably the oldest mask in the world (Musée de la bible et Terre Sainte )

Category: Image - :Ravensburg Fasnet Papierkrattler 2005.jpg|thumb|Papierkrattler masks at the Narrensprung 2005 Carnival parade, Ravensburg, Germany

A mask is an article normally worn on the face, typically for protection, concealment, performance, or amusement. Masks have been used since antiquity for both ceremonial and practical purposes. They are usually worn on the face, although they may also be positioned for effect elsewhere on the wearer's body, so in parts of Australia giant totem masks cover the body, whilst Inuit women use finger masks during storytelling and dancing. The Living Tradition of Yup'ik Masks; Anne Feinup-Riordan; University of Washington Press, Seattle, 1996; ISBN 10-0295975016

Category: File - :Camouflaged-sniper.jpg|thumb|275px|right|A camouflaged sniper, an example of military camouflage

Camouflage is a method of crypsis - avoidance of observation - that allows an otherwise visible organism or object to remain indiscernible from the surrounding environment through deception. Examples include a tiger's stripes and the battledress of a modern soldier. The theory of camouflage covers the various strategies which are used to achieve this effect.

A was a covert agent or mercenary of feudal Japan specializing in unorthodox arts of war. The functions of the ninja included espionage, sabotage, infiltration, and assassination, as well as open combat in certain situations. The ninja, with their underhanded tactics, were contrasted with the samurai, who were careful not to tarnish their reputable image.

In his Buke My?mokush?, military historian Hanawa Hokinoichi writes of the ninja:

The origin of the ninja is obscure and difficult to determine, but can be surmised to be around the 14th century. Few written records exist to detail the activities of the ninja. The word shinobi did not exist to describe a ninja-like agent until the 15th century, and it is unlikely that spies and mercenaries prior to this time were seen as a specialized group. In the unrest of the Sengoku period (15th - 17th centuries), mercenaries and spies for hire arose out of the Iga and K?ga regions of Japan, and it is from these clans that much of later knowledge regarding the ninja is inferred. Following the unification of Japan under the Tokugawa shogunate, the ninja descended again into obscurity. However, in the 17th and 18th centuries, manuals such as the Bansenshukai (1676) ? often centered around Chinese military philosophy ? appeared in significant numbers.; based on different readings, Ninpiden is also known as Shinobi Hiden, and Bansenshukai can also be Mansenshukai. These writings revealed an assortment of philosophies, religious beliefs, their application in warfare, as well as the espionage techniques that form the basis of the ninja's art. The word ninjutsu would later come to describe a wide variety of practices related to the ninja.

The mysterious nature of the ninja has long captured popular imagination in Japan, and later the rest of the world. Ninjas figure prominently in folklore and legend, and as a result it is often difficult to separate historical fact from myth. Some legendary abilities include invisibility, walking on water, and control over natural elements. The ninja is also prevalent in popular culture, appearing in many forms of entertainment media.

Stealth technology also known as LO technology (low observable technology) is a sub-discipline of military tactics and passive electronic countermeasures Rao, G.A., & Mahulikar, S.P., (2002) Integrated review of stealth technology and its role in airpower, Aeronautical Journal, v. 106(1066), pp. 629-641., which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, in order to make them less visible (ideally invisible) to radar, infrared Mahulikar, S.P., Sonawane, H.R., & Rao, G.A., (2007) Infrared signature studies of aerospace vehicles, Progress in Aerospace Sciences, v. 43(7-8), pp. 218-245., sonar and other detection methods.

Development in the United States occurred in 1958,Merlin, P.W. "Design and Development of the Blackbird: Challenges and Lessons Learned" American Institute of Aeronautics and Astronautics 47th AIAA Aerospace Sciences Meeting Including The New Horizons Forum and Aerospace Exposition 5 - 8 January 2009, Orlando, Florida. Accessed 2009-10-06. where earlier attempts in preventing radar tracking of its U-2 spy planes during the Cold War by the Soviet Union had been unsuccessful.Cadirci, S. "RF Stealth (Or Low Observable) and Counter- RF Stealth Technologies: Implications of Counter- RF Stealth Solutions for Turkish Air Force." Naval Postgraduate School, Monterey California, Ph.D. Thesis. March 2009. Accessed 6 October 2009. Designers turned to develop a particular shape for planes that tended to reduce detection, by redirecting electromagnetic waves from radars. Radar absorbent material was also tested and made to reduce or block radar signals that "bounced" off from the surface of planes. Such changes to shape and surface composition form stealth technology as currently deployed on the B-2 Spirit "Stealth Bomber". Billions of dollars have also been spent in developing stealth over a number of decades but the U.S. has been the only country economically able to do this.

The concept of stealth is to operate or hide without giving enemy forces any indications as to the presence of friendly forces. This concept was first explored through camouflage by blending into the background visual clutter. As the potency of detection and interception technologies (radar, IRST, surface-to-air missiles etc.) have increased over time, so too has the extent to which the design and operation of military personnel and vehicles have been affected in response. Some military uniforms are treated with chemicals to reduce their infrared signature. A modern "stealth" vehicle will generally have been designed from the outset to have reduced or controlled signature. Varying degrees of stealth can be achieved. The exact level and nature of stealth embodied in a particular design is determined by the prediction of likely threat capabilities.

Category: File - :Batesplate ArM.jpg|right|thumb|200px|Plate from Henry Walter Bates (1862) illustrating Batesian mimicry between Dismorphia species (top row, third row) and various Ithomiini (Nymphalidae) (second row, bottom row).

MimicryLess commonly known as mimetism. is the similarity in appearance of one species to another that affords one or both protection.King R.C. Stansfield W.D. & Mulligan P.K. 2006. A dictionary of genetics, 7th ed. Oxford. p278

Mimicry occurs when a group of organisms,This 'group' is often a species, but can also be a subgroup such as one particular sex or morph the mimics, have evolved to share common perceived characteristics with another group, the models.In its broadest definition mimicry can include non-living models. The evolution is driven by the selective action of a signal-receiver, or dupe. An example would be birds, using their vision to try and eat the palatable insects (the mimics), whilst avoiding the noxious models.

Collectively, this situation is known as a mimicry complex. The model is usually another species except in cases of automimicry. The signal-receiver is typically another intermediate organism like the common predator of two species, but may actually be the model itself, such as a moth resembling its spider predator. (includes video) As an interaction, mimicry is in most cases advantageous to the mimic and harmful to the receiver, but may increase, reduce or have no effect on the fitness of the model depending on the situation. Models themselves are difficult to define in some cases, for example eye spots may not bear resemblance to any specific organism's eyes, and camouflage often cannot be attributed to any particular model.

Category: File - :Mimicry of Siphanta acuta edit1.jpg|thumb|left|A planthopper mimics a leaf (mimesis)

Camouflage, in which a species appears similar to its surroundings, is essentially a form of visual mimicry, but usually is restricted to cases where the model is non-living or abiotic. In between camouflage and mimicry is mimesis, in which the mimic takes on the properties of a specific object or organism, but one to which the dupe is indifferent. The lack of a true distinction between the two phenomena can be seen in animals that resemble twigs, bark, leaves or flowers, in that they are often classified as camouflaged (a plant constitutes its "surroundings"), but are sometimes classified as mimics (a plant is also an organism). Crypsis is a broader concept that encompasses all forms of detection evasion, such as mimicry, camouflage, hiding etc.

Though mimicry is most obvious to humans in visual mimics, others senses such as olfaction (smell) or hearing may be involved, and more than one type of signal may be employed.Wickler, W. 1968. Mimicry in plants and animals. McGraw-Hill, New York Mimicry may involve morphology, behavior, and other properties. In any case, the signal always functions to deceive the receiver by preventing it from correctly identifying the mimic. In evolutionary terms, this phenomenon is a form of co-evolution usually involving an evolutionary arms race, and should not be confused with convergent evolution, which occurs when species come to resemble one another independently due to similar lifestyles.

Mimics may have multiple models during different stages of their life cycle, or they may be polymorphic, with different individuals imitating different models. Models themselves may have more than one mimic, though frequency dependent selection favors mimicry where models outnumber mimics. Models tend to be relatively closely related organisms, but mimicry of vastly different species is also known. Most known mimics are insects, though many other animal mimics including mammals are known. Plants and fungi may also be mimics, though less research has been carried out in this area.Boyden, T. C. (1980) Floral Mimicry by Epidendrum ibaguense (Orchidaceae) in Panama Evolution 34:135-136.Roy, B. A. (1994) The Effects of Pathogen-Induced Pseudoflowers and Buttercups on Each Other's Insect Visitation Ecology 75:352-358.Wickler, Wolfgang (1998). ?Mimicry?. Encyclopædia Britannica, 15th edition. Macropædia 24, 144?151. http://www.britannica.com/eb/article-11910