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Species · Colorado · BBS 2026 Release · 1966–2025

Lesser Goldfinch Population Trend in Colorado

All statesForest birds

Lesser Goldfinch in Colorado has surged: up 290% on the route-weighted index since 1972.

+290%Since 1972TrendPercent 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 →
80Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lesser 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 →

Lesser Goldfinch has surged in Colorado: up 290% on the route-weighted index since 1972.

Lesser Goldfinch Population Forecast in Colorado

If the recent trend holds, Lesser Goldfinch in Colorado is projected to rise about 28% by 2030 — from 0.99 in 2025 to a central estimate of 1.3 (95% range 0.55–2.0). A 5-year backtest shows a typical error of ±25.2%, with 100% of held-out values landing inside the 95% band.

+28%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 →
1.3Projected 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 →
0.55–2.095% 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 →
±25.2%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, Lesser Goldfinch in Colorado is projected to rise about 28% by 2030 — from 0.99 in 2025 to a central estimate of 1.3 (95% range 0.55–2.0). A 5-year backtest shows a typical error of ±25.2%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20261.20.501.9
20271.20.511.9
20281.20.531.9
20291.30.542.0
20301.30.552.0

Lesser Goldfinch Survey Routes in Colorado

Routes recording Lesser 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 →
Cokedale2120251995
Cone Mtn1220182008
Gold Hill1120122002
Cortez1020081992
Ludlow1020251998
Walsenburg920251994
Yampa820231990
Wet Mtns.820251994
Yellowjacket Pass820252021
Gold Hill 2820252018
Douglas Pass620241985
Falfa520251972
Gribbles Prk520251994
Tarryall420252009
Rosevale420232009
Piedra420072007
Harmony320251978
Delta320151980
Last Chance 2320252018
Pagosa Spgs219741969
Fruita220002000
Castleton220232002
Crowley220212012
Dolores Riv220222022
Trinchera220251990

Lesser Goldfinch Population Trend in Other States

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