Data from: Distance-dependent pattern blending can camouflage salient aposematic signals



The effect of viewing distance on the perception of visual texture is well known: spatial frequencies higher than the resolution limit of an observer's visual system will be summed and perceived as a single combined colour. In animal defensive colour patterns, distance-dependent pattern blending may allow aposematic patterns, salient at close range, to match the background to distant observers. Indeed, recent research has indicated that reducing the distance from which a salient signal can be detected can increase survival over camouflage or conspicuous aposematism alone. We investigated whether the spatial frequency of conspicuous and cryptically coloured stripes affects the rate of avian predation. Our results are consistent with pattern blending acting to camouflage salient aposematic signals effectively at a distance. Experiments into the relative rate of avian predation on edible model caterpillars found that increasing spatial frequency (thinner stripes) increased survival. Similarly, visual modelling of avian predators showed that pattern blending increased the similarity between caterpillar and background. These results show how a colour pattern can be tuned to reveal or conceal different information at different distances, and produce tangible survival benefits.,visual_model_dataVisual model output for viewing caterpillar and background colourssurvival_yellowSurvival data (avian predation rate) for yellow-and-black striped caterpillarssurvival_greenSurvival data (avian predation rate) for green-and-black striped caterpillarsdetection_yellowDetection data (supplementary material) for yellow-and-black striped caterpillarsdetection_greenDetection data (supplementary material) for green-and-black striped caterpillars,
Date made available2 Jun 2017

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