The evolution of colour polymorphism in British winter‐active Lepidoptera in response to search image use by avian predators

Phenotypic polymorphism in cryptic species is widespread. This may evolve in response to search image use by predators exerting negative frequency‐dependent selection on intraspecific colour morphs, “apostatic selection”. Evidence exists to indicate search image formation by predators and apostatic selection operating on wild prey populations, though not to demonstrate search image use directly resulting in apostatic selection. The present study attempted to address this deficiency, using British Lepidoptera active in winter as a model system. It has been proposed that the typically polymorphic wing colouration of these species represents an anti‐search image adaptation against birds. To test (a) for search image driven apostatic selection, dimorphic populations of artificial moth‐like models were established in woodland at varying relative morph frequencies and exposed to predation by natural populations of birds. In addition, to test (b) whether abundance and degree of polymorphism ar...隐蔽物种（cryptic species）的表型多态性广泛存在。该类多态性的演化，可能由捕食者借助搜索图像（search image）对种内颜色形态施加负频率依赖选择所驱动，这类选择即被称为“反常选择（apostatic selection）”。已有研究证据显示，捕食者可形成搜索图像，且野生猎物种群中存在反常选择作用，但尚未有研究直接证实搜索图像的使用会直接引发反常选择。本研究以英国冬季活动的鳞翅目（Lepidoptera）昆虫为模式系统，旨在填补这一研究空白。已有假说提出，这类昆虫典型的多态性翅色，是针对鸟类的反搜索图像适应性策略。为验证（a）搜索图像驱动的反常选择，研究人员在林地中设置了相对形态频率各异的双态人工蛾类模型种群，并将其置于野生鸟类的捕食压力下。此外，为验证（b）种群丰度与多态性程度是否……