Birds
Black-and-White Warbler
Mniotilta varia · also called black and white warblers
A small, striped bird creeps headfirst down a tree trunk, probing bark crevices exactly the way a nuthatch would, and for a moment it is easy to forget that the black-and-white warbler is a warbler at all rather than some entirely different kind of bird.
Overview
The black-and-white warbler, Mniotilta varia, is a distinctively patterned songbird native to deciduous and mixed forest habitat across much of Canada and the eastern United States. Its bold black-and-white striping, unusual nuthatch-like bark-foraging style, and status as one of the earliest warblers to arrive each spring make it one of the more immediately recognisable warblers in North America.
A warbler built for climbing bark
While nearly every other warbler forages by gleaning leaves in the canopy or shrubs, the black-and-white warbler has evolved short legs and long hind claws suited specifically to creeping along trunks and branches, a niche almost entirely its own among North American warblers.
Status
Least Concern — widespread and stable across suitable deciduous and mixed forest habitat throughout much of Canada and the eastern United States.
Black-and-White Warbler: common questions
Why does the black-and-white warbler climb trees like a nuthatch?
This species forages by creeping along tree trunks and branches, often headfirst down a trunk, probing bark crevices for hidden insects rather than gleaning leaves the way most other warblers do, a foraging style made possible by its relatively short legs and unusually long hind claws, which give it the grip needed to cling securely to bark.
How can you identify a black-and-white warbler?
Look for a bird entirely striped in black and white over its whole body, a simple but distinctive pattern unlike the more colourful plumage of most other warblers, combined with its unmistakable habit of creeping along tree trunks and branches like a nuthatch rather than foraging among leaves.
When does the black-and-white warbler arrive in spring?
This species is typically one of the earliest warblers to return north each spring, often arriving well before many other warbler species have completed their own migration, a timing pattern that makes it one of the first warblers many birders spot each year.
What does the black-and-white warbler's song sound like?
The male produces a thin, high-pitched, repetitive song often described as sounding like a squeaky wheel turning, a distinctive and easily learned song quite different from the richer, more varied songs typical of many other warbler species.