Barn owl color morphs hunt differently in moonlight

Bright coloration in predators presents a paradox: being highly visible should reduce hunting success, yet vivid colors persist in species that rely on stealth. Camouflage, which minimizes contrast with the background, and startle coloration, where sudden brightness disrupts prey escape, have been proposed to explain this paradox. Barn owls ( Tyto alba ) are polymorphic, ranging from dark reddish to bright white, offering a natural experiment. Using high-resolution biologging, we tracked 69 free-ranging males across 354 nights and recorded 17,600 hunting attempts during chick provisioning. We tested whether plumage color mediates moonlight-dependent hunting behavior and performance. White males reduced exposure under dim conditions but, under bright moonlight, oriented attacks toward the Moon and favored bright periods and unshaded sites throughout the night. Red males showed weaker or no adjustments and remained comparatively cryptic. Although per-attack success did not differ across the lunar gradient, white males achieved higher nightly prey capture rates and shorter foraging bouts under bright moonlight. Together with previous work, these patterns are more consistent with the startle hypothesis than with a pure background-matching scenario, suggesting that conspicuous plumage can be incorporated into a light-dependent hunting strategy and that variation in lunar lightscapes may influence the evolution of animal coloration.