In order to fly, bird feathers have to be renewed periodically. Feathers of the new born change over time to feathers suitable for adult life. Feathers are the brightest and finest during the courtship period when the male is competing with other males for attention. Feathers differ significantly for certain species between the breeding and nonbreeding seasons. During breeding season (usually in the spring) the birds are more easily identified as many field guides highlight the breeding plumages. The photos that will be added below will illustrate some of the differences between breeding and nonbreeding plumages.