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Species · Massachusetts · BBS 2026 Release · 1966–2025

Black-and-white Warbler Population Trend in Massachusetts

All statesForest birds

Black-and-white Warbler in Massachusetts has increased: up 36% on the route-weighted index since 1968.

+36%Since 1968TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
32Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-and-white Warbler Trends in MassachusettsNotable 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 in Massachusetts. See the full index history below.

Black-and-white Warbler Population Forecast in Massachusetts

If the recent trend holds, Black-and-white Warbler in Massachusetts is projected to fall about 27% by 2030 — from 4.6 in 2025 to a central estimate of 3.3 (95% range 2.0–4.7). A 5-year backtest shows a typical error of ±14.3%, with 100% of held-out values landing inside the 95% band.

-27%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
3.3Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
2.0–4.795% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±14.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Black-and-white Warbler in Massachusetts is projected to fall about 27% by 2030 — from 4.6 in 2025 to a central estimate of 3.3 (95% range 2.0–4.7). A 5-year backtest shows a typical error of ±14.3%, with 100% of held-out values landing inside the 95% band.19662030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20263.42.04.7
20273.42.04.7
20283.42.04.7
20293.42.04.7
20303.32.04.7

Black-and-white Warbler Survey Routes in Massachusetts

Routes recording Black-and-white Warbler in Massachusetts.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Chesterfield1820251967
N Orange1520251968
Belchertown1120251967
Monterey1020252019
Pittsfield920161967
Cheshire819941969
Cummington720141968
S Barre620251968
Ware River620221993
Hancock620151997
Cummington 2520252015
Prattville320191966
Princeton319761969
Cape Cod Ns319961989
Wellfleet 2320252016
Warren 2320252010
Chilmark219831969
Marion220231969
Wellfleet220071966
Warren220081968
Sheffield220221971
N. Andover220051995
E Dennis120161967
Brockton120071967
Newburyport120151967

Black-and-white Warbler Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawaregeorgiaillinoisindianakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.