scholarly journals Disruptive contrast in animal camouflage

2006 ◽  
Vol 273 (1600) ◽  
pp. 2433-2438 ◽  
Author(s):  
Martin Stevens ◽  
Innes C Cuthill ◽  
Amy M.M Windsor ◽  
Hannah J Walker
Keyword(s):  
Background Luminance ◽  
High Contrast ◽  
Early Literature ◽  
Background Matching ◽  
Disruptive Coloration ◽  
Average Luminance ◽  
Intuitive Idea ◽  
Colour Patterns

Camouflage typically involves colour patterns that match the background. However, it has been argued that concealment may be achieved by strategic use of apparently conspicuous markings. Recent evidence supports the theory that the presence of contrasting patterns placed peripherally on an animal's body (disruptive coloration) provides survival advantages. However, no study has tested a key prediction from the early literature that disruptive coloration is effective even when some colour patches do not match the background and have a high contrast with both the background and adjacent pattern elements (disruptive contrast). We test this counter-intuitive idea that conspicuous patterns might aid concealment, using artificial moth-like targets with pattern elements designed to match or mismatch the average luminance (lightness) of the trees on which they were placed. Disruptive coloration was less effective when some pattern elements did not match the background luminance. However, even non-background-matching disruptive patterns reduced predation relative to equivalent non-disruptive patterns or to unpatterned controls. Therefore, concealment may still be achieved even when an animal possesses markings not found in the background. Disruptive coloration may allow animals to exploit backgrounds on which they are not perfectly matched, and to possess conspicuous markings while still retaining a degree of camouflage.

scholarly journals Contrasting coloration in terrestrial mammals

2008 ◽  
Vol 364 (1516) ◽  
pp. 537-548 ◽  
Author(s):  
Tim Caro
Keyword(s):  
Temperature Regulation ◽  
Functional Significance ◽  
The Body ◽  
Sexual Dichromatism ◽  
Black And White ◽  
Terrestrial Mammals ◽  
Background Matching ◽  
Disruptive Coloration ◽  
Colour Patterns ◽  
Pelage Coloration

Here I survey, collate and synthesize contrasting coloration in 5000 species of terrestrial mammals focusing on black and white pelage. After briefly reviewing alternative functional hypotheses for coloration in mammals, I examine nine colour patterns and combinations on different areas of the body and for each mammalian taxon to try to identify the most likely evolutionary drivers of contrasting coloration. Aposematism and perhaps conspecific signalling are the most consistent explanations for black and white pelage in mammals; background matching may explain white pelage. Evidence for contrasting coloration is being involved in crypsis through pattern blending, disruptive coloration or serving other functions, such as signalling dominance, lures, reducing eye glare or in temperature regulation has barely moved beyond anecdotal stages of investigation. Sexual dichromatism is limited in this taxon and its basis is unclear. Astonishingly, the functional significance of pelage coloration in most large charismatic black and white mammals that were new to science 150 years ago still remains a mystery.

Microhabitat use and body size drive the evolution of colour patterns in snapping shrimps (Decapoda: Alpheidae: Alpheus)

2019 ◽  
Author(s):  
Marco A M Elias ◽  
Arthur Anker ◽  
Felipe M Gawryszewski
Keyword(s):  
Body Size ◽  
Luminance Contrast ◽  
Microhabitat Use ◽  
Generalist Species ◽  
Categorical Analysis ◽  
Background Matching ◽  
Disruptive Coloration ◽  
Motion Dazzle ◽  
Colour Patterns ◽  
Snapping Shrimps

Abstract Background matching and disruptive coloration are common strategies used by animals to increase concealment, whereas motion-dazzle may prevent capture after recognition. Studies have related background matching to habitat dependency and survival success, whereas for animals with highly contrasting patterns it has been shown that they are able to explore a broader range of habitats due to disruptive coloration, and possibly via motion-dazzle. However, the effects of these strategies are likely to be influenced by body size and to work better for smaller species. We applied phylogenetic comparative methods to test the hypothesis that smaller snapping shrimps (genus Alpheus) with high-contrast stripes would be able to utilize more microhabitats than non-striped and larger species. We used a published phylogeny of the American species of Alpheus, studies that have described alpheid microhabitats and size, and high-resolution photographs of each species in the phylogeny. Our categorical analysis suggested that generalist snapping shrimps are more likely to have stripes than specialist shrimps, and this effect was stronger in smaller species. Similarly, we found an interacting effect of body size and habitat use on the degree of luminance contrast: smaller generalist species had higher contrast values than average-sized and habitat-specialist species. Therefore, predators, body size and frequency of microhabitats are likely to have influenced the evolution of colour patterns in Alpheus.

scholarly journals Evolutionary fine-tuning of background-matching camouflage among geographical populations in the sandy beach tiger beetle

2020 ◽  
Vol 287 (1941) ◽  
pp. 20202315
Author(s):  
Nayuta Yamamoto ◽  
Teiji Sota
Keyword(s):  
Sequence Data ◽  
Evolutionary Process ◽  
Fine Tuning ◽  
Colour Pattern ◽  
Tiger Beetle ◽  
Background Matching ◽  
Geographical Populations ◽  
Geographical Distances ◽  
The Japanese Archipelago ◽  
Colour Patterns

Background-matching camouflage is a widespread adaptation in animals; however, few studies have thoroughly examined its evolutionary process and consequences. The tiger beetle Chaetodera laetescripta exhibits pronounced variation in elytral colour pattern among sandy habitats of different colour in the Japanese Archipelago. In this study, we performed digital image analysis with avian vision modelling to demonstrate that elytral luminance, which is attributed to proportions of elytral colour components, is fine-tuned to match local backgrounds. Field predation experiments with model beetles showed that better luminance matching resulted in a lower attack rate and corresponding lower mortality. Using restriction site-associated DNA (RAD) sequence data, we analysed the dispersal and evolution of colour pattern across geographical locations. We found that sand colour matching occurred irrespective of genetic and geographical distances between populations, suggesting that locally adapted colour patterns evolved after the colonization of these habitats. Given that beetle elytral colour patterns presumably have a quantitative genetic basis, our findings demonstrate that fine-tuning of background-matching camouflage to local habitat conditions can be attained through selection by visual predators, as predicted by the earliest proponent of natural selection.

scholarly journals Outline and surface disruption in animal camouflage

2008 ◽  
Vol 276 (1657) ◽  
pp. 781-786 ◽  
Author(s):  
Martin Stevens ◽  
Isabel S Winney ◽  
Abi Cantor ◽  
Julia Graham
Keyword(s):  
Body Shape ◽  
Luminance Contrast ◽  
The Body ◽  
Maximum Effect ◽  
High Contrast ◽  
High Luminance ◽  
Effective Surface ◽  
Avian Predators ◽  
Disruptive Coloration ◽  
Visual Mechanism

Camouflage is an important strategy in animals to prevent predation. This includes disruptive coloration, where high-contrast markings placed at an animal's edge break up the true body shape. Successful disruption may also involve non-marginal markings found away from the body outline that create ‘false edges’ more salient than the true body form (‘surface disruption’). However, previous work has focused on breaking up the true body outline, not on surface disruption. Furthermore, while high contrast may enhance disruption, it is untested where on the body different contrasts should be placed for maximum effect. We used artificial prey presented to wild avian predators in the field, to determine the effectiveness of surface disruption, and of different luminance contrast placed in different prey locations. Disruptive coloration was no more effective when comprising high luminance contrast per se , but its effectiveness was dramatically increased with high-contrast markings placed away from the body outline, creating effective surface disruption. A model of avian visual edge processing showed that surface disruption does not make object detection more difficult simply by creating false edges away from the true body outline, but its effect may also be based on a different visual mechanism. Our study has implications for whether animals can combine disruptive coloration with other ‘conspicuous’ signalling strategies.

scholarly journals Empirical tests of the role of disruptive coloration in reducing detectability

2007 ◽  
Vol 274 (1615) ◽  
pp. 1325-1331 ◽  
Author(s):  
Stewart Fraser ◽  
Alison Callahan ◽  
Dana Klassen ◽  
Thomas N Sherratt
Keyword(s):  
Field Experiments ◽  
Human Subjects ◽  
Common Features ◽  
Background Matching ◽  
Disruptive Coloration ◽  
Oak Trees ◽  
Empirical Tests ◽  
Body Shapes ◽  
Better Than

Disruptive patterning is a potentially universal camouflage technique that is thought to enhance concealment by rendering the detection of body shapes more difficult. In a recent series of field experiments, artificial moths with markings that extended to the edges of their ‘wings’ survived at higher rates than moths with the same edge patterns inwardly displaced. While this result seemingly indicates a benefit to obscuring edges, it is possible that the higher density markings of the inwardly displaced patterns concomitantly reduced their extent of background matching. Likewise, it has been suggested that the mealworm baits placed on the artificial moths could have created differential contrasts with different moth patterns. To address these concerns, we conducted controlled trials in which human subjects searched for computer-generated moth images presented against images of oak trees. Moths with edge-extended disruptive markings survived at higher rates, and took longer to find, than all other moth types, whether presented sequentially or simultaneously. However, moths with no edge markings and reduced interior pattern density survived better than their high-density counterparts, indicating that background matching may have played a so-far unrecognized role in the earlier experiments. Our disruptively patterned non-background-matching moths also had the lowest overall survivorship, indicating that disruptive coloration alone may not provide significant protection from predators. Collectively, our results provide independent support for the survival value of disruptive markings and demonstrate that there are common features in human and avian perception of camouflage.

scholarly journals Background matching and disruptive coloration as habitat-specific strategies for camouflage

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Natasha Price ◽  
Samuel Green ◽  
Jolyon Troscianko ◽  
Tom Tregenza ◽  
Martin Stevens
Keyword(s):  
Background Matching ◽  
Disruptive Coloration

scholarly journals Disruptive coloration provides camouflage independent of background matching

2006 ◽  
Vol 273 (1600) ◽  
pp. 2427-2432 ◽  
Author(s):  
H. Martin Schaefer ◽  
Nina Stobbe
Keyword(s):  
Body Shape ◽  
The Body ◽  
Cognitive Mechanisms ◽  
Proximate Mechanisms ◽  
Background Matching ◽  
Prey Recognition ◽  
Heterogeneous Habitats ◽  
Disruptive Coloration ◽  
Fitness Benefits ◽  
Better Than

Natural selection shapes the evolution of anti-predator defences, such as camouflage. It is currently contentious whether crypsis and disruptive coloration are alternative mechanisms of camouflage or whether they are interrelated anti-predator defences. Disruptively coloured prey is characterized by highly contrasting patterns to conceal the body shape, whereas cryptic prey minimizes the contrasts to background. Determining bird predation of artificial moths, we found that moths which were dissimilar from the background but sported disruptive patterns on the edge of their wings survived better in heterogeneous habitats than did moths with the same patterns inside of the wings and better than cryptic moths. Despite lower contrasts to background, crypsis did not provide fitness benefits over disruptive coloration on the body outline. We conclude that disruptive coloration on the edge camouflages its bearer independent of background matching. We suggest that this result is explainable because disruptive coloration is effective by exploiting predators' cognitive mechanisms of prey recognition and not their sensory mechanisms of signal detection. Relative to disruptive patterns on the body outline, disruptive markings on the body interior are less effective. Camouflage owing to disruptive coloration on the body interior is background-specific and is as effective as crypsis in heterogeneous habitats. Hence, we hypothesize that two proximate mechanisms explain the diversity of visual anti-predator defences. First, disruptive coloration on the body outline provides camouflage independent of the background. Second, background matching and disruptive coloration on the body interior provide camouflage, but their protection is background-specific.

scholarly journals Camouflage through behavior in moths: the role of background matching and disruptive coloration

2014 ◽  
Vol 26 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Changku Kang ◽  
Martin Stevens ◽  
Jong-yeol Moon ◽  
Sang-Im Lee ◽  
Piotr G. Jablonski
Keyword(s):  
Background Matching ◽  
Disruptive Coloration

scholarly journals Background complexity can mitigate poor camouflage

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Zeke W. Rowe ◽  
Daniel J. D. Austin ◽  
Nicol Chippington ◽  
William Flynn ◽  
Finn Starkey ◽  
...  
Keyword(s):  
Habitat Preferences ◽  
Visual Complexity ◽  
Tree Bark ◽  
Background Luminance ◽  
Bird Predation ◽  
Background Matching ◽  
Bird Vision ◽  
In The Wild ◽  
Visual Clutter ◽  
Natural Complexity

Avoiding detection through camouflage is often key to survival. However, an animal's appearance is not the only factor affecting conspicuousness: background complexity also alters detectability. This has been experimentally demonstrated for both artificially patterned backgrounds in the laboratory and natural backgrounds in the wild, but only for targets that already match the background well. Do habitats of high visual complexity provide concealment to even relatively poorly camouflaged animals? Using artificial prey which differed in their degrees of background matching to tree bark, we were able to determine their survival, under bird predation, with respect to the natural complexity of the background. The latter was quantified using low-level vision metrics of feature congestion (or ‘visual clutter’) adapted for bird vision. Higher background orientation clutter (edges with varying orientation) reduced the detectability of all but the poorest background-matching camouflaged treatments; higher background luminance clutter (varying achromatic lightness) reduced average mortality for all treatments. Our results suggest that poorer camouflage can be mitigated by more complex backgrounds, with implications for both camouflage evolution and habitat preferences.

Sign in / Sign up

Export Citation Format

Share Document