BirdAnalyst
Species · Vermont · BBS 2026 Release · 1966–2025

Black-and-white Warbler Population Trend in Vermont

All statesForest birds

Black-and-white Warbler in Vermont has surged: up 158% on the route-weighted index since 1968.

+158%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 →
26Routes 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 VermontNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Black-and-white Warbler has surged in Vermont: up 158% on the route-weighted index since 1968.

Black-and-white Warbler Population Forecast in Vermont

If the recent trend holds, Black-and-white Warbler in Vermont is projected to stay roughly flat through 2030, near 3.7 (95% range 1.7–5.6). A 5-year backtest shows a typical error of ±16.4%, with 100% of held-out values landing inside the 95% band.

+1%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 →
3.7Projected 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 →
1.7–5.695% 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 →
±16.4%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 Vermont is projected to stay roughly flat through 2030, near 3.7 (95% range 1.7–5.6). A 5-year backtest shows a typical error of ±16.4%, 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 →
20263.61.65.6
20273.61.75.6
20283.61.75.6
20293.71.75.6
20303.71.75.6

Black-and-white Warbler Survey Routes in Vermont

Routes recording Black-and-white Warbler in Vermont.
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 →
Gaysville2120251966
Newbury 2820232005
Marlboro620251966
Hardwick620241967
Stowe620241988
Post Mills520251966
Hinesburg519941977
St Johnsbury420251970
East Haven420251967
Middlesex420251968
Bristol420251995
S Wallingfrd320221969
Greensboro320251967
Fletcher320251968
North Pownal220251966
Shaftsbury220251968
W Rutland220251972
East Calais220251966
Newbury220021987
Waterville219801979
Stratton120251966
Landgrove120251966
S Reading120241966
Northfld Fls120251980
Colchester120091986

Black-and-white Warbler Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawaregeorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsinwyoming

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