Setophaga castanea
Order Passeriformes
Family Parulidae
♂ Adult male.— Top of head chestnut, bordered in front and on the side with black; back streaked with black; throat, breast, and sides chestnut; sides of neck and rest of under parts buffy; wingbars white.
♀ Adult female.— Upper parts olive, streaked with black; under parts buffy; sides of breast tinged with reddish-brown.
♂ Immature male.— Similar to adult female; flanks with a tinge of reddish-brown.
♀Immature female.— Upper parts olive-green, usually unstreaked; flanks usually without tinge of reddish-brown; under parts buffy.
Nest, in coniferous trees, fifteen to twenty feet from the ground.
Eggs, white, tinged with greenish, and finely speckled about the larger end with brown.
The Bay-breasted Warbler, as a migrant, is not uncommon in the Hudson Valley and in western Massachusetts, but is generally very rare in eastern New England, where it occurs, as a rule, only when there is an unusually heavy migration of warblers. It passes north in the middle of May and returns in September. It breeds commonly on the high mountains of northern New England and in the extensive coniferous forests of northern and eastern Maine. The song of the Bay-breast suggests somewhat that of the Black and White Warbler, or the short form of the Redstart’s song.
This is the only warbler that has a chestnut crown, throat, breast, and sides; the Yellow Red poll has a chestnut crown and slight streaking of chestnut on its yellow under parts; the Chestnut-side has a narrow stripe of chestnut along the sides, but a yellow crown and a white throat. In September a few Bay-breasts pass through eastern Massachusetts, and a larger number through the Hudson Valley. They now resemble the immature Black-poll Warblers so closely that only a trained eye can distinguish them. The buffy tinge over the under parts, the buffy under tail-coverts, and occasionally the tinge of reddish brown along the sides are their distinguishing marks.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)