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C Alejandro Párraga

Publications and source records attributed to C Alejandro Párraga.

2 recordsLinked to original sources

The effectiveness of disruptive coloration as a concealment strategy.

Our understanding of camouflage has been developing for over 100 years. Several underlying principles have emerged. Background pattern matching, or crypsis, is insufficient to conceal objects because of edge information. Other strategies exist to disrupt the continuity of extended edges. These strategies are reviewed. We pay particular attention to the theory of disruptive coloration, which predicts that high-contrast elements located at the object edge will mask the perception of a target as belonging to a certain category of object, in spite of the fact that the edge elements are independently visible. Although this strategy has long been assumed to be effective, there has been a lack of supportive data involving the perception of targets by nonhuman animals. We present evidence, from a field study, in support of the notion that disruptive coloration reduces the chances of bird predation of artificial "moths."

Adaptation, Biological↗

Disruptive coloration and background pattern matching.

Effective camouflage renders a target indistinguishable from irrelevant background objects. Two interrelated but logically distinct mechanisms for this are background pattern matching (crypsis) and disruptive coloration: in the former, the animal's colours are a random sample of the background; in the latter, bold contrasting colours on the animal's periphery break up its outline. The latter has long been proposed as an explanation for some apparently conspicuous coloration in animals, and is standard textbook material. Surprisingly, only one quantitative test of the theory exists, and one experimental test of its effectiveness against non-human predators. Here we test two key predictions: that patterns on the body's outline should be particularly effective in promoting concealment and that highly contrasting colours should enhance this disruptive effect. Artificial moth-like targets were exposed to bird predation in the field, with the experimental colour patterns on the 'wings' and a dead mealworm as the edible 'body'. Survival analysis supported the predictions, indicating that disruptive coloration is an effective means of camouflage, above and beyond background pattern matching.

Adaptation, Biological↗