Short answer
Background matching, disruptive coloration and countershading are distinct mechanisms, and each now has field experiments behind it: artificial prey with edge-breaking patterns survive bird predation better than matching alone, countershaded model caterpillars are attacked less than plain ones, and released dark peppered moths are eaten more often than pale ones on clean bark. The experiments mostly use models, so they show that a pattern can protect — on that background, against those predators.
Background matching means the animal's colours and pattern resemble a random sample of what is behind it, so nothing marks it out. Disruptive coloration is logically separate: bold, contrasting patches, especially ones that touch the body's edge, break up the outline so that the shape is not recognised even where individual patches are visible. Countershading is a gradient, darker on the surface that faces the light, which cancels the shading that would otherwise reveal a rounded body. A fourth, masquerade, is resemblance to a specific uninteresting object such as a twig. An animal may use several at once. They make different predictions, which is what allows them to be tested separately.
Disruptive coloration had been textbook material for a century with almost no quantitative test. In 2005, artificial moth-like targets — triangular card 'wings' with a dead mealworm as the edible body — were pinned to oak trees and exposed to wild birds, and their survival was recorded over 24 hours. The targets were printed in brown and black, in colours and proportions chosen to match oak bark; what varied was whether the dark markings overlapped the outline or were displaced inwards, and how strongly they contrasted. Targets with markings on the edge survived better than those with the markings placed inside the outline, and high contrast enhanced the effect. The conclusion drawn was that disruption conceals over and above background matching.
The design compared the same colours with the markings in different places. Its limit is that card triangles do not choose where to rest.
A uniformly coloured caterpillar lit from above is brighter on top and shadowed below, and the gradient gives away its cylindrical form. Countershading — pigment graded so the lit side is darker — should cancel that. Artificial caterpillar-like prey were placed on the upper surfaces of beech branches where free-living birds could find them. Countershaded prey were attacked less than uniformly dark, uniformly light or reverse-shaded ones. The result held when the prey were fixed to the underside of branches with the shading reversed to suit, mimicking the resting posture of many real caterpillars. This is direct evidence that the gradient itself reduces predation, though it does not establish which visual cue the birds lose.
The peppered moth is the best-known case of colour evolving under predation, and for a time the evidence behind it was strongly criticised. A six-year experiment released 4,864 moths at their natural resting positions and recorded what birds took. On present-day, unpolluted bark the dark form was eaten at a higher rate, with daily selection against it of about 0.1 — enough to account for its decline since clean-air legislation. For seasonally white animals the evidence is observational but points the same way: radio-collared snowshoe hares mismatched with snow cover had weekly survival up to 7% lower. Both cases concern which of two colours survives better where, which is the core prediction of background matching.
Iridescence looks like the opposite of concealment. Yet when real jewel-beetle wing cases were fixed to baited models and set out on leaves, iridescent models survived bird predation better than models in any of the single colours the iridescence spans, and human searchers found them less often. The authors argue that changing colour and gloss interfere with recognising the target as an object. At the other end of the evidence scale, cuttlefish camouflage has been shown by hyperspectral imaging to match the background closely as modelled for fish vision — a measurement of resemblance, not yet a measurement of who gets eaten. A good match is a prediction of the camouflage hypothesis, not a test of its consequence.
| Mechanism | Study | Prey used | What was varied | Outcome measured | Result | Limit |
|---|---|---|---|---|---|---|
| Disruptive coloration | Cuthill and others, 2005 | Card moth shapes with a mealworm, on oak trees | Whether contrasting patches touched the outline; contrast level | Survival under wild bird predation | Edge-placed, high-contrast patterns survived best | Artificial prey |
| Countershading | Rowland and others, 2008 | Artificial caterpillar-like prey on beech branches | Shading: countershaded, uniform or reversed | Attacks by free-living birds | Countershaded prey attacked least, on top of or beneath the branch | Artificial prey; one woodland |
| Background matching | Cook and others, 2012 | 4,864 live peppered moths of both forms | Colour form released at natural resting sites | Predation by birds | Dark form taken more often on clean bark; daily selection about 0.1 | One site over six years |
| Iridescence as camouflage | Kjernsmo and others, 2020 | Baited models carrying real beetle wing cases | Iridescent against single-colour and matt treatments | Bird predation; detection by human searchers | Iridescent models survived best and were found least | Static models; one species |
| Seasonal background matching | Zimova and others, 2016 | Radio-collared wild snowshoe hares | Nothing: natural mismatch between coat and snow was recorded | Weekly survival | Mismatched hares had survival up to 7% lower per week | Observational |
| Organism | Colour | Proposed function | Evidence grade | What the evidence is |
|---|---|---|---|---|
| Peppered moth, dark form (Biston betularia f. carbonaria) | Sooty black, against the typical form's speckled pale grey | Concealment from birds on dark, soot-covered bark. | Experimentally tested | A six-year release of 4,864 moths found stronger bird predation on the dark form on today's cleaner bark, with daily selection of about 0.1 against it. |
| Asian jewel beetle (Sternocera aequisignata) | Iridescent green shifting to blue and purple | Camouflage: changing colour and gloss make the outline hard to pick out. | Experimentally tested | In two field experiments, models carrying real iridescent wing cases survived bird predation best and were hardest for human searchers to find; the authors argue camouflage explains it better than warning colour. |
| Snowshoe hare (Lepus americanus) | Brown in summer, white in winter | Camouflage against snow. | Comparative or correlational | Radio-collared hares mismatched with their background had weekly survival up to 7% lower. Moult start dates did not shift with snow. |
| Common cuttlefish (Sepia officinalis) | Yellow, red-brown and dark brown patterns that change in under a second | Camouflage from fish predators. | Comparative or correlational | Hyperspectral imaging with models of fish vision shows a close spectral and pattern match; survival was not measured. The animal itself is reported to be colour-blind. |
| Green hairstreak (Callophrys rubi) | Matt leaf green | Concealment on foliage has been suggested for green gyroid scales. | Proposed, untested in cited work | The cited papers establish structure and optics; neither tests predation. |
| White scarab beetle (Cyphochilus spp.) | Brilliant matt white | Concealment among white fungi has been suggested. | Proposed, untested in cited work | The cited work measures light transport; the ecological suggestion is untested there. |
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
FactStrong evidence
In a field experiment with artificial moth-like targets exposed to wild bird predation, targets with contrasting pattern elements on the body's outline survived better than targets with background-matching patterns alone, and higher contrast enhanced the effect.
Caveat: Artificial prey on oak trees, a detail taken from a later paper's description of the experiment; the result shows the pattern can protect, not how often real animals rely on it.
Source: Disruptive coloration and background pattern matching; Empirical tests of the role of disruptive coloration in reducing detectability
FactStrong evidence
Countershaded artificial caterpillar-like prey placed on beech branches were attacked less by free-living birds than uniformly coloured prey, including when attached to the underside of branches.
Caveat: Artificial prey in one woodland.
Source: Can't tell the caterpillars from the trees: countershading enhances survival in a woodland
FactStrong evidence· Madingley, near Cambridge, England
A six-year release experiment involving 4,864 peppered moths found strong differential bird predation against the melanic form, with daily selection of about 0.1 against it, sufficient to explain the decline of melanism in post-industrial Britain.
Source: Selective bird predation on the peppered moth: the last experiment of Michael Majerus
FactModerate evidence
In two field experiments, models bearing iridescent jewel-beetle wing cases survived bird predation better and were detected less often by human searchers than non-iridescent models, with camouflage identified as the most likely explanation.
Caveat: One study, one beetle species, static baited models on leaves.
Source: Iridescence as camouflage
Colourwise interpretationStrong evidence
A close visual match to the background, however carefully measured, is a precondition for camouflage and not a demonstration of it; only a difference in detection or survival between matched and mismatched prey tests the function.
Based on: Colourwise's distinction between the cuttlefish imaging study, which quantifies resemblance, and the moth, caterpillar and beetle experiments, which quantify predation.
Source: Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators; Animal camouflage: current issues and new perspectives
Reviewed 6 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.