Setophaga castanea
male
The Bay-breasted Warbler is a well-marked songbird, males being particularly colorful. The sexes are dissimilar. Adult summer males have a dark, streaked back and nape, and dark wings with two white wingbars. The crown, throat, chest, and flanks are chestnut, the face is black, and the side of the neck is buff. The underparts are otherwise creamy white. Adult summer females recall an adult male, but chestnut and black elements of the plumage are mainly replaced with gray-buff. In fall, adults of both sexes are similar to an adult summer female but less heavily streaked. Immatures are similar to a fall adult female, but duller still, and with only faint streaking on the back, and buff underparts that include the undertail. The legs are dark in all birds. Immature Blackpoll Warblers, which are similar to immature Bay-breasted Warblers, have pinkish-orange legs.
The Bay-breasted Warbler breeds across much of forested northern North America mainly from May to August. It spends the rest of the year in Central America. Its breeding success is linked to the abundance or otherwise of spruce budworm.
female
FACT FILE
LENGTH 5.5 in (14 cm)
FOOD Invertebrates, notably spruce budworms (larvae of moths in the genus Choristoneura)
HABITAT Mature spruce forests
STATUS Widespread and common summer visitor
VOICE Song is a series of five or more high-pitched whistling tswee notes. Call is a thin tssip
