Morphological characters such as wing length and body mass often correlate with life history parameters in avian biology, aefct the probability of acquiring a mate, timing of reproduction, success in obtaining extrapair copulation or survival. We measured biometrics in common rosenfich Carpodacus erythrinus among three age groups (Juveniles about 3-month old, yearlings, adults > 2 y) during autumn migration in central China. We found that body measurements changed with age, yearling males have shortest wing length in three groups and similar to adult female, express female-like wing length and plumage coloration. Juveniles have relative longer wing to support their rfist migration; yearlings have female-like body traits (wing length and plumage coloration) to avoid attacks from adult males in breeding season and increase maneuverability to escape predation risks. Adults have the longest wing, which could support their early arrival at wintering ground in migration. Our studies suggest that body size in juveniles is fully developed and the yearling males display female mimicry in wing length which is an adaptive strategy to sexual selection.