is complete, the body of the male is a brilliant lemon yellow, a color produced by carotenoid pigments from plant materials in its diet, with a striking jet black cap and white rump that is visible during flight. The female is mostly brown, lighter on the underside with a yellow bib. After the autumn molt, the bright summer feathers are replaced by duller plumage, becoming buff below and olive-brown above, with a pale yellow face and bib. The autumn plumage is almost identical in both sexes, but the male has yellow shoulder patches. The immature bird has a dull brown back, and the underside is pale yellow. The shoulders and tail are a dull black with buff-colored, rather than white, markings on wings and rump. This coloration is the same in both sexes. The song is a series of musical warbles and twitters, often with a long note. A tsee-tsi-tsi-tsit call is often given in flight; it may also be described as per-chic-o-ree. While the female incubates the eggs, she calls to her returning mate with a soft continuous tee-tee-tee-tee-tee sound. The young begin to use a call of chick-kee or chick-wee shortly before fledging, which they use until they have left the nest entirely. There are two defense calls made by adults during nesting; a sweet call made to rally other goldfinches to the nest and distract predators, and a bearbee used to signal to the nestlings to quiet them and get them to crouch down in the nest to become less conspicuous. Distribution and habitat The American goldfinch prefers open country where weeds thrive, such as fields, meadows, flood plains, as well as roadsides, orchards, and gardens. It may also be found in open deciduous and riparian woodlands and areas of secondary growth. This habitat preference continues during the spring and autumn migrations. The summer breeding range stretches across North America from coast to coast. It is bounded on the north by Saskatchewan and stretches south across North America to North Carolina on the east coast, and northern California on the west coast. The American goldfinch is a short-distance migrant, moving south in response to colder weather and lessened food supply. According to ornithologist Marc Parnell, this responsive, southerly migratory pattern is thought to begin to occur as daily low temperatures approach freezing, and particularly as these temperatures near 0 °F. The migration is completed in compact flocks,