Morph-specific selection drives phenotypic divergence in color polymorphic tawny owls (Strix aluco) in Northern Europe.

ABSTRACT: There is a long tradition in using genetically based color polymorphisms in natural populations to study evolutionary processes. Despite growing evidence for continuous phenotypic variation within discrete morphs, we still know little about how this shapes selective dynamics. Here, using 43 years of plumage color data from a Finnish tawny owl population (Strix aluco), we show that gray and brown morphs exhibit substantial intra-morph variation, which has diverged over time. Plumage in the brown morph became increasingly pigmented, while the gray morph showed an abrupt shift toward lighter coloration. By examining both adult and offspring plumage, we identified morph-specific drivers of these trends: in gray owls, reduced pigmentation appears linked to extreme winters that eroded standing g

SUBMITTER: Passarotto A 

PROVIDER: S-EPMC12827955 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature