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Color polymorphism is an adaptive strategy in which a species exhibits multiple color phenotypes in a population. Often, phenotypes are variably suited to different environmental conditions which may buffer the population against variable conditions. Modern climate change is creating novel selective pressures for many species, especially in winter habitats. Few studies have quantified the benefits of polymorphism for allowing species to cope with climate‐induced environmental change, particularly for species with more cryptic differences between morphs. We investigated how color polymorphism mediates selective pressures in ruffed grouse Bonasa umbellus, a winter‐adapted bird species of North American forests. Ruffed grouse display phenotypic variation in plumage color, ranging from red to gray. Over five winters (2015–2022), we monitored weather conditions, habitat use, and weekly survival for 94 grouse to test whether individuals had lower survival when phenotypically mismatched with snow cover (e.g. a gray bird on a snowless landscape or a red bird in snow). Grouse phenotypically mismatched with snow cover had lower survival, but only when winter survival rates were lowest. During winters of lower overall survival, red grouse exhibited higher survival during snow‐free periods, whereas gray grouse had higher survival when snow was present. We also found that open habitat negatively impacted survival, regardless of color. While the effect of phenotypic mismatch was variable among years, it was a stronger predictor of survival than land cover, suggesting that snow is an important habitat feature mediating overwinter survival. Our work offers an advancement in understanding how environmental variability affects geographic variation in and maintenance of multiple color phenotypes in seasonally‐snow covered environments. Our finding that interactions between color morph and snow cover are important for conferring winter survival provides further evidence that color polymorphism may serve as a buffer against rapidly changing conditions and a pathway for persistence of polymorphic species. Keywords: Bonasa umbellus, color polymorphism, phenotypic mismatch, ruffed grouse, winter ecology, Wisconsin [ABSTRACT FROM AUTHOR]

Animals are facing novel 'timescapes' in which the stimuli entraining their daily activity patterns no longer match historical conditions due to anthropogenic disturbance. However, the ecological effects (e.g., altered physiology, species interactions) of novel activity timing are virtually unknown. We reviewed 1328 studies and found relatively few focusing on anthropogenic effects on activity timing. We suggest three hypotheses to stimulate future research: (i) activity-timing mismatches determine ecological effects, (ii) duration and timing of timescape modification influence effects, and (iii) consequences of altered activity timing vary biogeographically due to broad-scale variation in factors compressing timescapes. The continued growth of sampling technologies promises to facilitate the study of the consequences of altered activity timing, with emerging applications for biodiversity conservation. Recent years have seen a growing interest in the role of time in structuring biological patterns and processes. Among nature's most dramatic and universal temporal patterns are the daily activity patterns shown by organisms. Although the endogenous mechanisms (e.g., circadian rhythms) giving rise to such patterns have been researched extensively, ecological aspects of daily activity patterns are now receiving greater attention. Plasticity in daily activity patterns may represent an in situ adaptation to human-mediated stressors such as climate change and urbanization. However, the effects of novel activity timing, which may emerge at multiple levels of biological organization, are poorly understood. We offer hypotheses to catalyze future research on the ecological consequences of altered daily activity timing and discuss approaches that may facilitate such investigations. [ABSTRACT FROM AUTHOR]