Disruptive coloration

The importance of high-contrast patterns for successful disruption was predicted in general terms by the artist Abbott Thayer in 1909 and explicitly by the zoologist Hugh Cott in 1940.

Conversely, poisonous or distasteful animals that advertise their presence with warning coloration (aposematism) use patterns that emphasize rather than disrupt their outlines.

Thayer explained that:[2] Markings... of whatever sort, tend to obliterate,—to cancel, by their separate and conflicting pattern, the visibility of the details and boundaries of form....

"[3] He draws an analogy with a pickpocket who carefully distracts your attention, arguing that: The function of a disruptive pattern is to prevent, or to delay as long as possible, the first recognition of an object by sight... irregular patches of contrasted colours and tones ... tend to catch the eye of the observer and to draw his attention away from the shape which bears them.Further, Cott criticises unscientific attempts at camouflage, early in the Second World War, for not understanding the principles involved: Various recent attempts to camouflage tanks, armoured cars and the roofs of buildings with paint reveal an almost complete failure by those responsible to grasp the essential factor in the disguise of surface continuity and of contour.

Such work must be carried out with courage and confidence, for at close range objects properly treated will appear glaringly conspicuous.

But they are not painted for deception at close range, but at ranges at which ... bombing raids are likely... And at these distances differences of tint ... blend and thus nullify the effect and render the work practically useless.The pioneering work of Thayer and Cott is endorsed in the 2006 review of disruptive coloration by Martin Stevens and colleagues, which notes that they proposed a "different form of camouflage" from the traditional "strategy of background matching" proposed by authors such as Alfred Russel Wallace (Darwinism, 1889), Edward Bagnall Poulton (The Colours of Animals, 1890) and Frank Evers Beddard (Animal Coloration, 1895); Stevens observes that background matching on its own would always fail because of "discontinuities between the boundary of the animal and the background".

[4] Disruptive patterns use strongly contrasting markings such as spots or stripes to break up the outlines of an animal or military vehicle.

[8] Many poisonous or distasteful animals that advertise their presence with warning coloration (aposematism) use patterns that emphasize rather than disrupt their outlines.

[12] Conversely, far from hiding, 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.

T. J. Givnish and Simcha Lev-Yadun have proposed that leaf variegation with white spots may serve as camouflage in forest understory plants, where there is a dappled background.

Lev-Yadun has also suggested, however, that similar markings serve as conspicuous warning coloration in well-defended thorny plants of open habitats, where the background is uniformly bright.

Disruptive camouflage would have a clear evolutionary advantage in plants: they would tend to escape from being eaten by herbivores; and the hypothesis is testable.

[26] Secondly, the effectiveness of any pattern in disrupting a soldier's outlines varies with lighting, depending on the weather and the height of the sun in the sky.

A pattern printed with small patches of colour blends into a single perceived mass at a certain range, defeating the disruptive effect.

photo of a frogmouth in a tree
The coloration of the Papuan frogmouth Podargus papuensis , its outline disrupted by its plumage, its eye concealed in a stripe, is an effective anti-predator adaptation .
The principle of "maximum disruptive contrast" in Hugh Cott 's 1940 Adaptive Coloration in Animals , "showing the distractive effect upon the eye of patterns which contrast as violently as possible with the tone of their background". [ 1 ] The examples are of a fish, an antelope, and a bird.
Egyptian nightjar , Caprimulgus aegyptius , rests on the sand, protected by its coloration, immobility, and concealment of shadow as it faces the sun
Mexican vine snake , Oxybelis aeneus , conceals its eye with a coincident dark stripe , contrasting with its pale underside
Disruptive and distractive camouflage both rely on conspicuous markings, but differ in their mechanisms and so in the size and position of the markings for greatest effectiveness.
Opposite of disruption: Fire salamander , Salamandra salamandra , advertises its inedibility with bright warning colours , in patches that emphasize its body shape
photo of a giraffe mother and calf
A conspicuous giraffe mother can defend herself, but her calf relies on its camouflage
Irregular outline of comma butterfly Polygonia c-album avoids a typical butterfly shape
Many understory plants such as the saw greenbriar, Smilax bona-nox are variegated with pale markings which may serve as camouflage. [ 14 ]
photo of a soldier putting on camouflage face paint
A soldier applying a disruptive pattern to his face; his helmet and jacket are both disruptively patterned
US Woodland camouflage pattern
Modern German Flecktarn 1990 is a non-digital pattern designed to disrupt outlines at different distances