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

American Goldfinch Population Trend in Connecticut

All statesForest birds

American Goldfinch in Connecticut has surged: up 83% on the route-weighted index since 1968.

+83%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 →
20Routes 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 American Goldfinch Trends in ConnecticutNotable 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 →

American Goldfinch has surged in Connecticut: up 83% on the route-weighted index since 1968.

American Goldfinch Population Forecast in Connecticut

If the recent trend holds, American Goldfinch in Connecticut is projected to rise about 135% by 2030 — from 9.9 in 2025 to a central estimate of 23 (95% range 11–35). A 5-year backtest shows a typical error of ±74.3%, with 80% of held-out values landing inside the 95% band.

+135%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 →
23Projected 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 →
11–3595% 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 →
±74.3%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, American Goldfinch in Connecticut is projected to rise about 135% by 2030 — from 9.9 in 2025 to a central estimate of 23 (95% range 11–35). A 5-year backtest shows a typical error of ±74.3%, 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 →
2026221034
2027221034
2028231134
2029231135
2030231135

American Goldfinch Survey Routes in Connecticut

Routes recording American Goldfinch in Connecticut.
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 →
Warren12120111972
Buckingham2320221966
Sherman2320191972
Mystic2020231973
Willimantic2020181967
Long Hill1920191973
Greenwich1620181968
Danbury1620231968
Woodstock1520071968
Uncasville1420251977
Mid Haddam1420251973
E Hartland1219921967
Westbrook1020251969
Southington920251973
Granby920251988
Woodstock 2820252016
Warren 2820252012
No Woodbury720251967
New Hartford619871972
New Hartford620241994

American Goldfinch Population Trend in Other States

alabamaarkansascaliforniacoloradodelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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