Bird Database

Black-and-white Warbler

(Mniotilta varia)

State of the Birds
At a Glance





Strongly Decreasing


Habitat loss and fragmentation, Predation, Collisions

Conservation Actions

Manage forests for mid-successional stages, Maintain a bird-friendly yard

Black-and-white Warbler

(Mniotilta varia)

The standout feature of the Black-and-white Warbler is its habit of foraging along the trunks and limbs of trees like a nuthatch. They are aided in this behavior, as are nuthatches, by possessing a longer-than-usual hind claw and heavier legs. Their bill is also more strongly curved than those of most warblers, and helps them reach into bark crevices for caterpillars, beetles, insect eggs, and spiders. Even their genus translates as “moss plucker.” They are not restricted to foraging on bark however, and will frequently glean insects from foliage like other warblers.

For all the time they spend in trees, Black-and-white Warblers return to the ground to nest, building a neat cup of grass and pine needles at the base of a tree trunk or stump. The 3-5 eggs are incubated for 10-12 days, after which the parents feed the chicks for another 10-12 before they fledge.

Population trends for the Black-and-white Warbler are difficult to interpret. In much of the Northeast they were stable through the 1990s, only to drop precipitously through the early 2000s. After around 2005 they again stabilized or started to increase slightly. In contrast, trends to our west often involve a gradual increase in though the 1980s or beyond, and a more recent decrease. Since species has not been subject to extensive study, we don’t really know the degree to which it is sensitive to threats that affect other forest birds, particularly habitat fragmentation, increased predation, and changes in forest composition resulting from invasive species.

Seasonal Abundance

Relative abundance based on eBird data. Numbers indicate likelihood of finding this species in suitable habitat at a given time of year, not actual numbers encountered.

Black-and-white Warbler
Range Map

Information for the species profiles on this website was compiled from a combination of the sources listed below.

  • The Birds of New Hampshire. By Allan R. Keith and Robert B. Fox. 2013. Memoirs of the Nuttall Ornithological club No. 19.

  • Atlas of the Breeding Birds of New Hampshire. Carol R. Foss, ed. 1994. Arcadia Publishing Company and Audubon Society of New Hampshire

  • Birds of the World. Various authors and dates. Cornell Laboratory of Ornithology.

  • Data from the Breeding Bird Survey

  • Data from the Christmas Bird Count