| Black-and-white warbler | |
|---|---|
2.jpg) | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Parulidae |
| Genus: | Mniotilta Vieillot, 1816 |
| Species: | M. varia |
| Binomial name | |
| Mniotilta varia (Linnaeus, 1766) | |
 | |
| Range Breeding range Wintering range | |
| Synonyms | |
Motacilla variaLinnaeus, 1766 | |
Theblack-and-white warbler (Mniotilta varia) is a species ofNew World warbler, and the only member of its genus,Mniotilta. It breeds in northern and easternNorth America and winters in Florida,Central America, and theWest Indies down toPeru. This species is a very rare vagrant to westernEurope.[2] Relative to other New World warblers, it is not well studied.[3]
The black-and-white warbler wasformally described in 1766 by the Swedish naturalistCarl Linnaeus in thetwelfth edition of hisSystema Naturae under thebinomial nameMotacilla varia.[4][5] The specific epithet is fromLatinvarius meaning "various", "diverse" or "variegated".[6] Linnaeus based his entry of the "small black and white bird" that had been described by the Irish physicianHans Sloane in 1725 and "Le Figuier varié de S. Domingue" that had been described by the French ornithologistLouis Vieillot in 1760.[7][8] Linnaeus specified thelocation as Jamaica and Dominica but this was restricted toSanto Domingo in theDominican Republic by theAmerican Ornithologists' Union in 1910.[5][9] The black-and-white warbler is now the only species placed in thegenusMniotilta that was introduced by the French ornithologistLouis Vieillot in 1816.[10][11] The genus name combines theAncient Greek μνιον/mnion meaning "seaweed" (clearly an error for μνιοεις/mnioeis meaning "moss") and τιλλω/tillō meaning "to pluck".[12] The species ismonotypic: nosubspecies are recognised.[11]
The black-and-white warbler is known to hybridize with thecerulean warbler (Setophaga cerulea) andBlackburnian warbler (Setophaga fusca). However, it is not closely related to the genusSetophaga.[13]
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.[3][14] Wingspan ranges from 7.1 to 8.7 in (18–22 cm).[15] 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.[14]
This species is 12 cm (5 in) long and weighs 11 g (0.39 oz).[16][3] The summer male black-and-white warbler is boldly streaked in black and white, and the bird has been described as a flyinghumbug.[17] 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 theblackpoll 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 can also be confused behaviourally with thepine warbler (Setophaga pinus) andyellow-throated warbler (Setophaga dominica).[14][18]
The black-and-white warbler breeds in northern and eastern North America. It ranges from theNorthwest Territories to the northwest andNewfoundland and Labrador to the northeast, toNorth Carolina to the southeast andTexas to the southwest. This species ismigratory, wintering in Florida, Central America, the West Indies and northern South America down toPeru.[3] TheIUCN estimates the extent of occurrence, or range, to be 11,500,000 km2.[19] It occurs as a vagrant inIceland,Ireland,Faeroes, and theUK.[14][20]
It is a migratory species, breeding inNorth America and wintering in North andSouth America. It is typically found in deciduous forest in its breeding range, but becomes more of a habitat generalist in the non-breeding season.[3]
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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 includedeciduous 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 inriparian 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.[3] It has also been noted to winter in shade coffee plantations and gardens.[3][21] Males are territorial in both their summer and winter habitats.[22][23]
The black-and-white warbler has a high-pitched song, described as a repeatingwee-see that is repeated at least six times in succession. It has achip call as well as aseet-seet call that is sometimes given in flight.[14]Its song is a highsee wee-see wee-see wee-see wee-see wee-see orweesa weesa weetee weetee weetee weet weet weet. It has two calls, a hardtick and a soft, thinfsss.[2][16]
The black-and-white warbler feeds oninsects andspiders, and, unlike other warblers, forages like anuthatch, moving up and down tree trunks and along branches.[16] It feeds in a manner similar to a nuthatch or a creeper. It forages on tree trunks and limbs to feed on insects below the bark's surface.[18] Its short legs and long hind toe are adaptations to this foraging method.[18] The black-and-white warbler is unique among warblers in its time spent foraging on tree trunks and inner branches.[3] This bird also gleans, like many warblers, for insects.[14] Its diet is composed of insects and other arthropods, includinglepidopteran larvae, beetles, ants, and spiders.[24] During migration and breeding, this warbler relies heavily on lepidopteran larvae.[25] During migration, the black-and-white warbler sometimes joins mixed flocks to feed.[18]
The black-and-white warbler is of the first warblers to arrive to its spring breeding grounds.[18] In the southernmost range of its breeding habitat, it can begin breeding mid-April. Males are territorial and defend their territory, both by singing and chasing competitors away. When a female arrives in a male's territory, he pursues her in an effort to breed. The male may display by flapping his wings.[3]
It breeds in broadleaved or mixed forest, preferably in wetter areas. Black-and-white warblers nest on the ground, laying four or five eggs in a cup nest.[2] The nest is cup-shaped, often located on the ground among roots or against a tree, or in crevices on tree stumps. The species prefers to nest in damp areas. The nest is constructed with grassy material, bark, and dry leaves, and lined with softer material such as moss and hair. The female is responsible for most of the nest-building.[3] The female lays four or five eggs,[2] which are light brown and speckled with darker brown. The female begins incubating once the last or second-to-last egg is laid. Incubation lasts 10 to 12 days, and is done solely by the female. During incubation, the female is sometimes fed by the male. Both parents care for the nestlings. The young fledge after 8 to 12 days, and stay around the nest while they improve their flight ability. During this time, the parents remain nearby.[3] This species generally produces one brood per year.[26] The nests are sometimesparasitized by thebrown-headed cowbird (Molothrus ater).[3][18]
The IUCN classifies the black-and-white warbler as Least Concern due to its large range and population size. However, its population is decreasing.[19]Habitat loss and degradation, especially forest fragmentation, are the main factors contributing to the species' decline. Ifhabitat loss continues, in either or both summer or wintering habitat, the species may continue to decline in the future.[27][28] Pesticides such asfenitrothion andphosphamidon have contributed to the species' decline in the 1970s,[29] and others such as chlorinated hydrocarbons may continue to have an effect.[3]
