BirdAnalyst
Species · Connecticut · BBS 2025 Release · 1966–2024

American Goldfinch Population Trend in Connecticut

All statesGeneralists

American Goldfinch in Connecticut has surged: up 117% on the route-weighted index since 1968.

+117%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 →
58YearsYears 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 117% 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 56% by 2029 — from 15 in 2024 to a central estimate of 24 (95% range 12–35). A 5-year backtest shows a typical error of ±54.9%, with 100% of held-out values landing inside the 95% band.

+56%Change by 2029TrendPercent 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 →
24Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
12–3595% 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 →
±54.9%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, American Goldfinch in Connecticut is projected to rise about 56% by 2029 — from 15 in 2024 to a central estimate of 24 (95% range 12–35). A 5-year backtest shows a typical error of ±54.9%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025231134
2026231134
2027231235
2028241235
2029241235

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
Southington2920241973
Buckingham2320221966
Sherman2320191972
Mystic2020231973
Willimantic2020181967
Long Hill1920191973
Mid Haddam1920241973
Granby1820241988
Greenwich1620181968
Danbury1620231968
Woodstock1520071968
Westbrook1420241969
No Woodbury1420241967
Woodstock 21420242016
Uncasville1320241977
E Hartland1219921967
Warren 21120242012
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 2026-05-22.