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

Purple Finch Population Trend in Vermont

All statesForest birds

Purple Finch in Vermont has fallen sharply: down 65% on the route-weighted index since 1968.

-65%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 Purple Finch 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 →

Purple Finch has fallen sharply in Vermont: down 65% on the route-weighted index since 1968.

Purple Finch Population Forecast in Vermont

If the recent trend holds, Purple Finch in Vermont is projected to fall about 79% by 2030 — from 2.1 in 2025 to a central estimate of 0.44 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±63.9%, with 80% of held-out values landing inside the 95% band.

-79%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 →
0.44Projected 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 →
0.00–1.895% 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 →
±63.9%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, Purple Finch in Vermont is projected to fall about 79% by 2030 — from 2.1 in 2025 to a central estimate of 0.44 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±63.9%, 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 →
20260.640.002.0
20270.590.001.9
20280.540.001.9
20290.490.001.8
20300.440.001.8

Purple Finch Survey Routes in Vermont

Routes recording Purple Finch 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 →
East Haven720251966
Waterville619801968
Landgrove520251966
Middlesex420251969
East Calais420251966
Hardwick420161966
Greensboro420251967
Newbury 2420232005
Stratton320251966
S Reading320241966
Hinesburg319881966
Bristol320252009
Marlboro220251967
S Wallingfrd220141971
Newbury220041986
North Pownal120251966
Gaysville120121966
Post Mills120051967
Shaftsbury120241967
W Rutland120231968
St Johnsbury120251970
Northfld Fls120251980
Fletcher120251969
Colchester120251986
Grand Isle120001972

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiooregonpennsylvaniarhode-islandwashingtonwest-virginiawisconsin

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