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

Lesser Goldfinch Population Trend in Colorado

All statesGeneralists

Lesser Goldfinch in Colorado has surged: up 313% on the route-weighted index since 1972.

+313%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 →
79Routes 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 →
54YearsYears 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 313% 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 30% by 2029 — from 0.98 in 2024 to a central estimate of 1.3 (95% range 0.56–2.0). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.

+30%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 →
1.3Projected 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 →
0.56–2.095% 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 →
±18.7%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 30% by 2029 — from 0.98 in 2024 to a central estimate of 1.3 (95% range 0.56–2.0). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20251.20.501.9
20261.20.511.9
20271.20.532.0
20281.30.542.0
20291.30.562.0

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 →
Ludlow1720161998
Cokedale1620241995
Cone Mtn1220182008
Gold Hill1120122002
Cortez1020081992
Walsenburg1020241994
Yampa820231990
Falfa820241972
Gold Hill 2820242018
Westcliffe720241999
Douglas Pass620241985
Wet Mtns.620241994
De Beque520241992
Gribbles Prk520241994
Harmony420241978
Aspen420232007
Rosevale420232009
Piedra420072007
Elbert420241998
Animas 2420212006
Delta320151980
Kiowa 2320242019
Yellowjacket Pass320232021
Buford220231980
Pagosa Spgs219741969

Lesser Goldfinch Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.