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

Canada Warbler Population Trend in Vermont

All statesForest birds

Canada Warbler in Vermont has fallen sharply: down 73% on the route-weighted index since 1968.

-73%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 →
22Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Canada 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 declinecomputed 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 →

Canada Warbler has fallen sharply in Vermont: down 72% on the route-weighted index since 1968.

Canada Warbler Population Forecast in Vermont

If the recent trend holds, Canada Warbler in Vermont is projected to fall about 100% by 2030 — from 0.33 in 2025 to a central estimate of 0.00 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±71%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.8195% 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 →
±71%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, Canada Warbler in Vermont is projected to fall about 100% by 2030 — from 0.33 in 2025 to a central estimate of 0.00 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±71%, 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 →
20260.070.000.88
20270.050.000.86
20280.040.000.84
20290.020.000.82
20300.000.000.81

Canada Warbler Survey Routes in Vermont

Routes recording Canada 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 →
Waterville619801967
Landgrove219981968
S Wallingfrd220071994
East Haven220251967
Northfld Fls220111980
Newbury220031986
Marlboro119891967
North Pownal119931969
Stratton120231976
S Reading120041968
Gaysville120101967
Post Mills120071967
Shaftsbury119971973
W Rutland120251979
St Johnsbury120251970
Middlesex120251968
East Calais120241966
Hardwick120061966
Greensboro120131967
Fletcher120251975
Newbury 2120182010
Stowe120231988

Canada Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniarhode-islandtennesseevirginiawest-virginiawisconsin

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