Motion dazzle and camouflage as distinct anti-predator defenses. BMC Biol 9:81

Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
BMC Biology (Impact Factor: 7.98). 11/2011; 9(1):81. DOI: 10.1186/1741-7007-9-81
Source: PubMed


Camouflage patterns that hinder detection and/or recognition by antagonists are widely studied in both human and animal contexts. Patterns of contrasting stripes that purportedly degrade an observer's ability to judge the speed and direction of moving prey ('motion dazzle') are, however, rarely investigated. This is despite motion dazzle having been fundamental to the appearance of warships in both world wars and often postulated as the selective agent leading to repeated patterns on many animals (such as zebra and many fish, snake, and invertebrate species). Such patterns often appear conspicuous, suggesting that protection while moving by motion dazzle might impair camouflage when stationary. However, the relationship between motion dazzle and camouflage is unclear because disruptive camouflage relies on high-contrast markings. In this study, we used a computer game with human subjects detecting and capturing either moving or stationary targets with different patterns, in order to provide the first empirical exploration of the interaction of these two protective coloration mechanisms.
Moving targets with stripes were caught significantly less often and missed more often than targets with camouflage patterns. However, when stationary, targets with camouflage markings were captured less often and caused more false detections than those with striped patterns, which were readily detected.
Our study provides the clearest evidence to date that some patterns inhibit the capture of moving targets, but that camouflage and motion dazzle are not complementary strategies. Therefore, the specific coloration that evolves in animals will depend on how the life history and ontogeny of each species influence the trade-off between the costs and benefits of motion dazzle and camouflage.

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    • "Staudinger et al. (2013) also show that cuttlefishes adapt their cryptic behaviour according to the presence of various teleost predators. Multiple camouflaging techniques and anti-predator behaviours, such as the 'moving rock' are synergistically combined to yield the best cryptic result (Norman et al., 2001; Stevens et al., 2011). However, the question of camouflage and background matching during motion remains open. "
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    • "While there have now been several studies considering both the hypothesis of motion dazzle and more generally how patterning affects perceptual and behavioural judgements when in motion (reviewed in Table 1), there is still debate as to which strategies are optimal and what aspects of a target’s pattern are important in determining capture difficulty. In this study, we use human prey capture experiments similar to those conducted by Stevens and colleagues [17,21] to investigate these questions. We compare putative ‘motion dazzle’ transverse striped targets, different types of cryptic stimuli (uniform luminance matched grey and background matching targets) and highly conspicuous white targets to determine how these different patterning types compare in difficulty of capture. "
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    • "dated . There is likely to be a trade - off between animal conspicuousness and movement ; for example , motion dazzle markings are highly conspicuous when prey are stationary but provide protection when moving . In contrast , camouflage provides protection when station - ary , but the same markings may appear conspicuous when the ani - mal moves ( Stevens et al . 2011 ) . This may explain why most prey become immobile or " freeze " when threatened . A study on cuttle - fish found that individuals produced low - contrast patterns when moving , suggesting that the high - contrast patterns in motion dazzle may not impede capture ( Zylinski et al . 2009a ) . However , a target with markings that provide "

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