BirdAnalyst
Species · Colorado · BBS 2026 Release · 1966–2025

Spotted Towhee Population Trend in Colorado

All statesForest birds

Spotted Towhee in Colorado has surged: up 20× on the route-weighted index since 1971.

20×Since 1971TrendPercent 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 →
99Routes 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 Spotted 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 →

Spotted Towhee has surged in Colorado: up 20× on the route-weighted index since 1971.

Spotted Towhee Population Forecast in Colorado

If the recent trend holds, Spotted Towhee in Colorado is projected to stay roughly flat through 2030, near 7.1 (95% range 4.5–9.6). A 5-year backtest shows a typical error of ±16.2%, with 100% of held-out values landing inside the 95% band.

-10%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 →
7.1Projected 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 →
4.5–9.695% 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 →
±16.2%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, Spotted Towhee in Colorado is projected to stay roughly flat through 2030, near 7.1 (95% range 4.5–9.6). A 5-year backtest shows a typical error of ±16.2%, 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 →
20266.74.29.3
20276.84.29.4
20286.94.39.5
20297.04.49.6
20307.14.59.6

Spotted Towhee Survey Routes in Colorado

Routes recording Spotted 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 →
Mesaverde Np16220251996
Baxter Pass6420241994
Walsenburg5920251994
Douglas Pass5120241982
Angora4620251998
Wray Gulch4520251988
Yellowjacket Pass4220251998
Cokedale3920251995
Wilson Creek3220251990
Haycamp Mesa2920251998
Wet Mtns.2820251993
Nucla2820251999
Ludlow2420251998
Dinosaur2320251995
Yampa2020231975
Pinon2020251995
Gribbles Prk2020251994
De Beque1820251992
Rifle Falls1820251998
Ragged Mtn.1520191994
Mcphee Res.1520251996
Gardner1520251998
Cortez 21520172009
Rosevale1420252009
Animas 21320252005

Spotted Towhee Population Trend in Other States

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