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

Warbling Vireo Population Trend in Vermont

All statesForest birds

Warbling Vireo in Vermont has surged: up 82% on the route-weighted index since 1968.

+82%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 Warbling Vireo 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 →

Warbling Vireo has surged in Vermont: up 82% on the route-weighted index since 1968.

Warbling Vireo Population Forecast in Vermont

If the recent trend holds, Warbling Vireo in Vermont is projected to rise about 156% by 2030 — from 1.2 in 2025 to a central estimate of 3.1 (95% range 1.3–5.0). A 5-year backtest shows a typical error of ±65%, with 80% of held-out values landing inside the 95% band.

+156%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 →
3.1Projected 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 →
1.3–5.095% 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 →
±65%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, Warbling Vireo in Vermont is projected to rise about 156% by 2030 — from 1.2 in 2025 to a central estimate of 3.1 (95% range 1.3–5.0). A 5-year backtest shows a typical error of ±65%, with 80% 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 →
20263.01.24.9
20273.11.24.9
20283.11.25.0
20293.11.25.0
20303.11.35.0

Warbling Vireo Survey Routes in Vermont

Routes recording Warbling Vireo 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 →
Hinesburg1319941966
S Wallingfrd520221966
Waterville519801967
Shaftsbury420251966
W Rutland420251966
Grand Isle420241967
North Pownal320251978
Newbury320041988
S Reading220241966
Post Mills220251966
Middlesex220031968
Fletcher220251969
Bristol220251995
Marlboro120181966
Stratton120231968
Landgrove120251974
Gaysville120251977
St Johnsbury120251970
East Haven120251968
Northfld Fls120211980
East Calais120241974
Hardwick120241972
Greensboro120231973
Colchester120251986
Newbury 2120232005

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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