Family: Parulidae, Wood Warblers view all from this family

Description 4 1/2-5" (11-13 cm). Bright yellow with a light olive green tinge on back. Male has fine rusty streaks on breast. The only largely yellow warbler with yellow spots in the tail (not white).

Habitat Moist thickets, especially along streams and in swampy areas; gardens.

Nesting 4 or 5 pale blue eggs, thickly spotted with brown, in a well-made cup of bark, plant fibers, and down, placed in an upright fork in a small sapling.

Range Breeds from Alaska east across Canada to Newfoundland and south to southern California, northern Oklahoma, and northern Georgia; local in southern Florida. Winters in tropics.

Voice   Song a bright, musical sweet-sweet-sweet, sweeter-than-sweet. Call a sharp chip.

Discussion This is one of the most widespread of our warblers, showing great geographical variation. In the tropical parts of its breeding range this bird nests mainly in mangrove swamps, and there it may have a chestnut head or crown patch. In temperate North America the Yellow Warbler is one of the principal victims of the cowbird, which lays its eggs in the nests of other birds. A cowbird lays only one egg per foster nest, but she may lay eggs in four or five nests in a short time, thus jeopardizing many broods. If the female Yellow Warbler discovers a cowbird parasitizing her nest, she quickly covers the alien egg with a new foundation and lays another clutch. Occasionally a nest is found with up to six layers, each containing one cowbird egg.