Prothonotary Warbler

The prothonotary warbler is 13 cm (5.1 in) long, weighs a mean 14.3 g (0.50 oz), and has a wingspan of 22 cm (8.75 in). It has an olive-coloured back with blue-grey wings and tail, yellow underparts, a relatively long pointed bill, and black legs. The adult male has a bright orange-yellow head. Females and immature birds are duller and have a yellow head. In flight from below, the short, wide tail has a distinctive two-toned pattern, white at the base and dark at the tip.

The prothonotary warbler mostly breeds in hardwood swamps in extreme southeastern Ontario and the eastern United States. However, it may nest near other bodies of water such as creeks, streams, ponds, and swimming pools. The habitat of the warblers during migration is not well known. However, they are particularly prominent in Belize during spring migration. The warblers winter in the West Indies, Central America and northern South America, primarily in mangrove swamps. It is a rare vagrant to parts of the western United States, most notably California.

The prothonotary warbler is the only eastern warbler that nests in natural or artificial cavities, sometimes using old downy woodpecker holes. The male often builds several incomplete, unused nests in his territory; the female builds the real nest and lays 3–7 eggs. The preferred foraging habitat is dense, woody streams, where the prothonotary warbler forages actively in low foliage, mainly for insects and snails. The song of this bird is a simple, loud, ringing sweet-sweet-sweet-sweet-sweet. The call is a loud, dry chip, like that of a hooded warbler. Its flight call is a loud seeep.