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).