Black-and-white Warbler

The black-and-white warbler is 11 cm (4.3 in) to 13 cm (5.1 in) in length with a mass of 8 g (0.28 oz) to 15 g (0.53 oz) grams. Wingspan ranges from 7.1 to 8.7 in (18–22 cm). True to their name, black-and-white warblers are black and white in colour. Both sexes have black and white crowns with a white eyebrow, black streaking on a white belly, black wings with two white wing bars, a black tail, a black-and-white streaked back, streaky undertail coverts, and grey-black legs and feet. Breeding males have a black-and-white streaked throat and black cheek, while females have a grey cheek and a white-cream coloured throat and sides. First fall males are very similar to adult females in colour and patterning, while first fall females resemble adult females but with less streaking and a more noticeable buffy wash. Juveniles are heavily spotted, but are similar to first fall individuals otherwise. This species is 12 cm (5 in) long and weighs 11 g (0.39 oz). The summer male black-and-white warbler is boldly streaked in black and white, and the bird has been described as a flying humbug. Each wing is black with two white wing bars. Female and juvenile plumages are similar, but duller and less streaky than males. This warbler can be confused with the blackpoll warbler (Setophaga striata). The blackpoll warbler is also black and white in its summer plumage, but has a solid black cap. …

The black-and-white warbler breeds in northern and eastern North America. It ranges from the Northwest Territories to the northwest and Newfoundland and Labrador to the northeast, to North Carolina to the southeast and Texas to the southwest. This species is migratory, wintering in Florida, Central America, the West Indies and northern South America down to Peru. The IUCN estimates the extent of occurrence, or range, to be 11,500,000 km2. It occurs as a vagrant in Iceland, Ireland, Faeroes, and the UK. It is a migratory species, breeding in North America and wintering in North and South America. It is typically found in deciduous forest in its breeding range, but becomes more of a habitat generalist in the non-breeding season.

The species occupies a broad niche, and is found in a variety of habitats. In its breeding habitat, it prefers mature forest, but will occupy successional and second growth forest. Preferred forest types include deciduous and mixed forest, and this warbler sometimes occupies swampy forest. During migration, this species prefers forest to other land cover types and is frequently found in riparian areas. In its wintering habitat, it can be found in a variety of land cover types, from mangroves to wet, dry, and cloud forest. It occupies both successional and mature forest. It has also been noted to winter in shade coffee plantations and gardens. …

The black-and-white warbler feeds on insects and spiders, and, unlike other warblers, forages like a nuthatch, moving up and down tree trunks and along branches. It is the only North American wood-warbler to forage on bark. Its short legs and long hind toe are adaptations benefitting its foraging method. This bird also gleans, like many warblers, for insects. Its diet is composed of insects and other arthropods, including lepidopteran larvae, beetles, ants, and spiders. During migration and breeding, this warbler relies heavily on lepidopteran larvae. During migration, the black-and-white warbler sometimes joins mixed flocks to feed. It is known to occasionally eat anoles on its wintering grounds in the Caribbean.