BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Lesser Goldfinch Population Analysis

FringillidaeForest birdsSpinus psaltria

Lesser Goldfinch has surged: up 201% on the route-weighted index since 1969.

+201%Since 1969TrendPercent 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 →
701RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Lesser Goldfinch

The Lesser Goldfinch (Spinus psaltria) is a North American member of the Finches (Fringillidae). In this analysis it is grouped with the forest birds.

Size
4.5–6.5 in long (11–16 cm) — a small songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 701 Breeding Bird Survey routes across 11 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Fringillidae · Forest birds

Notable Lesser Goldfinch TrendsNotable 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 surveyed states: up 201% on the route-weighted index since 1969.

Lesser Goldfinch Population Forecast

If the recent trend holds, Lesser Goldfinch is projected to stay roughly flat through 2030, near 0.61 (95% range 0.28–0.94). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.

+2%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 →
0.61Projected 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 →
0.28–0.9495% 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 →
±15.5%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 is projected to stay roughly flat through 2030, near 0.61 (95% range 0.28–0.94). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.610.280.94
20270.610.280.94
20280.610.280.94
20290.610.280.94
20300.610.280.94

Where the Lesser Goldfinch Is Detected

BBS routes recording Lesser Goldfinch, sized by most recent count.

Lesser Goldfinch Population Trend by State

Lesser Goldfinch population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+145%197061
California+50%1970228
Colorado+290%197280
Idaho+99%20078
Nevada+980%198815
New Mexico+6%197076
Oregon-36%197148
Texas-24%1969117
Utah+69%198752
Washington+81%20145
Wyominginsufficient datan/a11

Lesser Goldfinch Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Lesser Goldfinch population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-50%197059
Great Basin+599%197074
Northern Rockies+552%200513
Sierra Nevada-11%197133
Southern Rockies / Colorado Plateau+201%1970149
Shortgrass Prairie+21%197340
Central Mixed Grass Prairie-27%196910
Edwards Plateau-9%196920
Oaks and Prairies-62%196919
Coastal California+99%1970116
Sonoran and Mojave Deserts+198%197050
Sierra Madre Occidental+47%197036
Chihuahuan Desert-71%197050
Tamaulipan Brushlands+219%197022
Gulf Coastal Prairie+4%19976

Lesser Goldfinch Conservation Status

Our route-weighted index shows it up about 201% since 1969.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.