Background complexity can mitigate poor camouflage

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 lab 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; hig...通过伪装（camouflage）规避被发现，往往是物种生存的核心要务。然而，动物的外观并非影响其显眼度的唯一因素：背景复杂度同样会改变其被探测的难易程度。此前已有实验分别针对实验室中的人工纹理背景与野外自然背景验证了这一结论，但仅适用于那些已与背景高度匹配的目标个体。那么，视觉复杂度较高的生境，能否为伪装效果相对较差的动物提供隐蔽呢？本研究使用与树皮背景匹配度各异的人工猎物，探究了鸟类捕食压力下猎物存活情况与背景自然复杂度之间的关联。背景自然复杂度通过适配鸟类视觉的特征拥挤（feature congestion，或称‘视觉杂乱’）低级视觉指标进行量化。更高的背景朝向杂乱度（即朝向各异的边缘）会降低除伪装匹配度最差处理组之外所有组别的猎物可探测性；高...