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Species · Utah · BBS 2026 Release · 1966–2025

Spotted Towhee Population Trend in Utah

All statesForest birds

Spotted Towhee in Utah has surged: up 219% on the route-weighted index since 1970.

+219%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 →
94Routes 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 UtahNotable 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 Utah: up 219% on the route-weighted index since 1970.

Spotted Towhee Population Forecast in Utah

If the recent trend holds, Spotted Towhee in Utah is projected to fall about 21% by 2030 — from 6.8 in 2025 to a central estimate of 5.4 (95% range 2.7–8.1). A 5-year backtest shows a typical error of ±41.2%, with 100% of held-out values landing inside the 95% band.

-21%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 →
5.4Projected 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 →
2.7–8.195% 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 →
±41.2%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 Utah is projected to fall about 21% by 2030 — from 6.8 in 2025 to a central estimate of 5.4 (95% range 2.7–8.1). A 5-year backtest shows a typical error of ±41.2%, 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 →
20265.22.57.9
20275.32.68.0
20285.32.68.0
20295.42.78.1
20305.42.78.1

Spotted Towhee Survey Routes in Utah

Routes recording Spotted Towhee in Utah.
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 →
Fayette6620251993
Hill Creek5719951993
Beck 23620251990
Newcastle3620251997
Hatch2720251994
La Sal 22720062003
Aneth2620251996
Bonanza2620151992
Main Canyon2620251987
Wellington2520021997
Altonah2320251970
Wellington 32120252012
Moab2120251986
Moquith Mtn1920241987
La Sal1720001996
Monticello1720251998
La Sal 31420252007
Bryce Canyon1320251990
Crawford Mts1320152015
Wellington 21320112003
Vernon1220251992
Book Ridge1120252003
Richfield1020191994
Ant Flat-Ogden Can920251994
Beaver820251979

Spotted Towhee Population Trend in Other States

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