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

American Goldfinch Population Trend in Colorado

All statesForest birds

American Goldfinch in Colorado has surged: up 192% on the route-weighted index since 1970.

+192%Since 1970TrendPercent 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 →
108Routes 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 American Goldfinch Trends in ColoradoNotable 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 Colorado: up 192% on the route-weighted index since 1970.

American Goldfinch Population Forecast in Colorado

If the recent trend holds, American Goldfinch in Colorado is projected to rise about 12% by 2030 — from 0.81 in 2025 to a central estimate of 0.92 (95% range 0.07–1.8). A 5-year backtest shows a typical error of ±35.4%, with 100% of held-out values landing inside the 95% band.

+12%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 →
0.92Projected 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 →
0.07–1.895% 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 →
±35.4%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 Colorado is projected to rise about 12% by 2030 — from 0.81 in 2025 to a central estimate of 0.92 (95% range 0.07–1.8). A 5-year backtest shows a typical error of ±35.4%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.910.061.7
20270.910.071.8
20280.910.071.8
20290.910.071.8
20300.920.071.8

American Goldfinch Survey Routes in Colorado

Routes recording American Goldfinch in Colorado.
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 →
Yampa6120231972
Deadman Rd.1820252011
Alamosa1320251988
Dolores Riv1020172012
Rifle Falls1020251999
Thomasville919931992
Yellowjacket Pass920251998
Adams Co.820221992
Flattops720062003
Limon720031992
Pinneo620191991
Cheesman Lk620251979
Buffalo Park620232011
Fort Morgan620251996
Bennett620151995
Dolores519871968
Colona419871977
Wilson Creek420251990
Kiowa 2420242019
Rockport420182013
Douglas Pass320241986
Kiowa320181968
Walden320251991
Hudson320231994
Villegreen320011996

American Goldfinch Population Trend in Other States

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

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