Black-and-white Warbler    Mniotilta varia

Migratory Status: Neotropical migrant

PIF Population Estimate: 14 000 000

Percent of western hemisphere population breeding in boreal forest: 53%

BAM Effective Detection Radius (m) : 52.5

PIF Maximum Detection Distance (m) : 100

Canadian BBS Population trend: -0.1 n.s. (-1.0 to 0.8)

Life History

The Black-and-white Warbler is the only member of the monotypic genus Mniotilta, which translates as “moss-plucking”, which refers to the species’ bark foraging habits. The specific name varia, or “variegated”, refers to the contrasting black and white appearance. Unlike other North American wood warblers, the Black-and-white Warbler has a unique foraging strategy, whereby it “creeps” along the trunk and branches of trees, much like a nuthatch (Sitta spp.). To facilitate this strategy, the Black-and-white Warbler has proportionately longer toes for its body size than most other members of the wood warbler family.

As the name suggests, the Black-and-white Warbler is strongly patterned with varying amounts of black and white streaking, depending on the age and sex of the individual. Adult males and females differ only slightly, with very little to no black markings on the undersides (belly and throat) in the latter. Immature birds resemble adult females during fall migration and have a distinct appearance amongst other migrant warblers. The song of the Black-and-white Warbler is a diagnostic series of 5 to 10 thin, high-pitched phrases, often paraphrased as “teesee, teesee, teesee” and likened to the sound of a squeaky wheel.

The breeding range extends over most of the eastern and central United States, and almost all of the forested regions of Canada, from southeastern Yukon Territory to Newfoundland. The winter range includes almost the entire coast of the Gulf of Mexico, including portions of Texas, Louisiana, and Florida in the United States. The winter range also includes Mexico, Central America, northwestern South America, and much of the Caribbean.

Throughout its breeding range, the Black-and-white Warbler is most often associated with deciduous-dominated or mixed deciduous-coniferous forests, often in moist to swampy forested wetlands with dense forest cover.

Reference(s)

Kricher, J. C. 1995. Black-and-white Warbler (Mniotilta varia), The Birds of North America, No.158. A. Poole and F. Gill, eds. The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists's Union, Washington, D.C.