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

Spotted Towhee Population Trend in Colorado

All statesGeneralists

Spotted Towhee in Colorado has surged: up 19× on the route-weighted index since 1971.

19×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 →
98Routes 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 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 19× 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 fall about 12% by 2029 — from 7.8 in 2024 to a central estimate of 6.9 (95% range 4.3–9.5). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.

-12%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 →
6.9Projected 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 →
4.3–9.595% 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 →
±19.3%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 fall about 12% by 2029 — from 7.8 in 2024 to a central estimate of 6.9 (95% range 4.3–9.5). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20256.64.09.1
20266.64.19.2
20276.74.19.3
20286.84.29.4
20296.94.39.5

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 Np14320241996
Baxter Pass6420241994
Douglas Pass5120241982
Angora4920241998
Ludlow3820161998
Cokedale3520241995
Yellowjacket Pass3220241998
Haycamp Mesa3120241998
Nucla2520241999
Wilson Creek2420241990
Yampa2020231975
Dinosaur2020241995
Walsenburg2020241994
Wet Mtns.1920241993
Piedra1920241992
Gribbles Prk1920241994
Wray Gulch1820231988
Black Sulphur Cr1720242015
De Beque1620241992
Ragged Mtn.1520191994
Westcliffe1520241998
Cortez 21520172009
Pinon1420241995
Paonia1320241992
Mcphee Res.1320241996

Spotted Towhee Population Trend in Other States

arizonacaliforniaidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwyoming

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