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

Blue-winged Warbler Population Trend in Vermont

All statesForest birds

Blue-winged Warbler in Vermont has declined: down 30% on the route-weighted index since 1992.

-30%Since 1992TrendPercent 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 →
5Routes 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 →
18YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blue-winged 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 →

No notable trend signals for Blue-winged Warbler in Vermont. See the full index history below.

Blue-winged Warbler Population Forecast in Vermont

If the recent trend holds, Blue-winged Warbler in Vermont is projected to rise about 114% by 2030 — from 0.06 in 2025 to a central estimate of 0.12 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±227.5%, with 100% of held-out values landing inside the 95% band.

+114%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 →
0.12Projected 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 →
0.00–0.3495% 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 →
±227.5%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, Blue-winged Warbler in Vermont is projected to rise about 114% by 2030 — from 0.06 in 2025 to a central estimate of 0.12 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±227.5%, with 100% of held-out values landing inside the 95% band.19842030
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 →
20260.120.000.35
20270.120.000.35
20280.120.000.35
20290.120.000.35
20300.120.000.34

Blue-winged Warbler Survey Routes in Vermont

Routes recording Blue-winged 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 →
Shaftsbury820001992
Fletcher220222022
North Pownal120251984
S Wallingfrd119991999
W Rutland120172003

Blue-winged Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckymarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandtennesseevirginiawest-virginiawisconsin

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