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Species · Colorado · BBS 2026 Release · 1966–2025

Green-tailed Towhee Population Trend in Colorado

All statesForest birds

Green-tailed Towhee in Colorado has risen sharply: up 68% on the route-weighted index since 1970.

+68%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 →
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 Green-tailed Towhee 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 →

Green-tailed Towhee has risen sharply in Colorado: up 68% on the route-weighted index since 1970.

Green-tailed Towhee Population Forecast in Colorado

If the recent trend holds, Green-tailed Towhee in Colorado is projected to stay roughly flat through 2030, near 9.4 (95% range 6.4–13). A 5-year backtest shows a typical error of ±12.5%, with 100% of held-out values landing inside the 95% band.

+9%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 →
9.4Projected 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 →
6.4–1395% 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 →
±12.5%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, Green-tailed Towhee in Colorado is projected to stay roughly flat through 2030, near 9.4 (95% range 6.4–13). A 5-year backtest shows a typical error of ±12.5%, 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 →
20269.26.112
20279.36.212
20289.36.212
20299.46.312
20309.46.413

Green-tailed Towhee Survey Routes in Colorado

Routes recording Green-tailed Towhee 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 →
Yampa9620231969
Mesaverde Np7320251996
Douglas Pass5220241982
Yellowjacket Pass4520251998
Black Sulphur Cr4320252015
Mcphee Res.4220251996
Heeney 24220252025
Powderhorn4120251994
Wray Gulch4020251988
Uncompahgre4020251988
Baxter Pass3920241994
Dinosaur2920251995
Deadman Rd.2720251992
Great Divide2620251974
Wilson Creek2620251990
Doyleville2620251988
Tarryall2520251988
Heeney2320192017
Moon Pass2220251998
Castleton2120251988
Angora2020251998
Paonia1920251992
Pagosa Spgs1819821968
Thomasville1720251993
Stillwater Pass1720091998

Green-tailed Towhee Population Trend in Other States

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