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

American Goldfinch Population Trend in Colorado

All statesGeneralists

American Goldfinch in Colorado has surged: up 186% on the route-weighted index since 1970.

+186%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 →
106Routes 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 →
56YearsYears 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 186% 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 98% by 2029 — from 0.46 in 2024 to a central estimate of 0.92 (95% range 0.07–1.8). A 5-year backtest shows a typical error of ±35.6%, with 100% of held-out values landing inside the 95% band.

+98%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 →
0.92Projected 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 →
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 →
±35.6%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 98% by 2029 — from 0.46 in 2024 to a central estimate of 0.92 (95% range 0.07–1.8). A 5-year backtest shows a typical error of ±35.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.910.061.8
20260.910.061.8
20270.920.071.8
20280.920.071.8
20290.920.071.8

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
Dolores Riv1020172012
Cheesman Lk920241979
Thomasville919931992
Adams Co.820221992
Blackhead Pk820212004
Flattops720062003
Limon720031992
Pinneo620191991
Buffalo Park620232011
Bennett620151995
Rifle Falls620211999
Dolores519871968
Deadman Rd.520242011
Colona419871977
Kiowa 2420242019
Rockport420182013
Douglas Pass320241986
Kiowa320181968
Hudson320231994
Alamosa320221988
Villegreen320011996
Cortez320081988
Dunckley Pas320241992
Yellowjacket Pass320241998

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 2026-05-22.