Plumage/ˈpluːmɪdʒ/ Definition 1 of 3Pro Tip 1/3Bird Species Plumage varies by bird species and can indicate age or sex. Male cardinals have brighter plumage than females. Pro Tip 2/3Display Purpose Birds may use plumage to attract mates or intimidate rivals. The bird puffed up its plumage to appear larger. Pro Tip 3/3Seasonal Change Some birds change plumage seasonally for camouflage or mating. Ducks have more colorful plumage during mating season.