Black-and-white Warbler Population Analysis
Black-and-white Warbler has increased: up 29% on the route-weighted index since 1968.
About the Black-and-white Warbler
The Black-and-white Warbler (Mniotilta varia) is a North American member of the Wood-Warblers (Parulidae). In this analysis it is grouped with the forest birds.
- Size
- 4.5–5.5 in long (11–14 cm) — a small, active songbird (typical for the family)
- Habitat
- Woodlands and forest edges, including wooded suburbs and parks.
- Diet
- Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
- Range
- Recorded on 1,514 Breeding Bird Survey routes across 36 states, most concentrated in the Appalachian Mountains.
- Family
- Parulidae · Forest birds
Notable Black-and-white Warbler TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →
No notable trend signals for Black-and-white Warbler. See the full index history below.
Black-and-white Warbler Population Forecast
If the recent trend holds, Black-and-white Warbler is projected to fall about 21% by 2030 — from 0.92 in 2025 to a central estimate of 0.73 (95% range 0.54–0.91). A 5-year backtest shows a typical error of ±20.8%, with 40% of held-out values landing inside the 95% band.
Where the Black-and-white Warbler Is Detected
BBS routes recording Black-and-white Warbler, sized by most recent count.
Black-and-white Warbler Population Trend by State
Black-and-white Warbler Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
Black-and-white Warbler Conservation Status
Our route-weighted index shows it up about 29% since 1968.
Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.