Figure 1. Predicted relationship between ruffed grouseBonasa umbellus overwinter survival and phenotypic mismatch caused by mismatch between plumage coloration (color morph) and snow presence or absence. (a) We predicted that gray morph birds would have lower survival during periods with less or patchier snow cover and red morph birds would have lower survival during periods of more persistent snow cover. (b) Ruffed grouse exhibit variation in plumage coloration with two predominant color morphs of red or gray, although intermediates frequently occur and differences are most pronounced in tail fan coloration. Photographs by Joanne King (left) and Simon Boivin (right).