Division of Psychology, Abertay University, Dundee, DD1 1HG, UK.
Curr Biol. 2013 Feb 4;23(3):260-4. doi: 10.1016/j.cub.2012.12.031. Epub 2013 Jan 17.
Camouflage is conferred by background matching and disruption, which are both affected by microhabitat. However, microhabitat selection that enhances camouflage has only been demonstrated in species with discrete phenotypic morphs. For most animals, phenotypic variation is continuous; here we explore whether such individuals can select microhabitats to best exploit camouflage. We use substrate selection in a ground-nesting bird (Japanese quail, Coturnix japonica). For such species, threat from visual predators is high and egg appearance shows strong between-female variation. In quail, variation in appearance is particularly obvious in the amount of dark maculation on the light-colored shell. When given a choice, birds consistently selected laying substrates that made visual detection of their egg outline most challenging. However, the strategy for maximizing camouflage varied with the degree of egg maculation. Females laying heavily maculated eggs selected the substrate that more closely matched egg maculation color properties, leading to camouflage through disruptive coloration. For lightly maculated eggs, females chose a substrate that best matched their egg background coloration, suggesting background matching. Our results show that quail "know" their individual egg patterning and seek out a nest position that provides most effective camouflage for their individual phenotype.
伪装是通过背景匹配和破坏来实现的，这两者都受到微生境的影响。然而，增强伪装的微生境选择仅在具有离散表型形态的物种中得到证明。对于大多数动物来说，表型变异是连续的；在这里，我们探讨了这些个体是否可以选择微生境来最大限度地利用伪装。我们使用了一种地面筑巢鸟类（日本鹌鹑，Coturnix japonica）的基质选择。对于这种物种来说，来自视觉捕食者的威胁很高，而且蛋的外观表现出强烈的雌性间变异。在鹌鹑中，外观上的变异在浅色壳上的暗色斑纹数量上尤为明显。当有选择时，鸟类总是选择那些使视觉探测到其蛋轮廓最具挑战性的产卵基质。然而，最大化伪装的策略因卵的斑点程度而异。产卵斑点多的雌性选择与卵斑点颜色特性更匹配的基质，从而通过破坏颜色实现伪装。对于斑点较少的蛋，雌性会选择最能与其蛋背景颜色相匹配的基质，这表明了背景匹配。我们的研究结果表明，鹌鹑“知道”它们自己的蛋图案，并寻找一个为其个体表型提供最有效伪装的巢位。
