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

Spotted Towhee Population Trend in Utah

All statesGeneralists

Spotted Towhee in Utah has surged: up 153% on the route-weighted index since 1970.

+153%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 →
93Routes 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 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 153% 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 rise about 11% by 2029 — from 4.7 in 2024 to a central estimate of 5.2 (95% range 2.5–7.9). A 5-year backtest shows a typical error of ±45.8%, with 100% of held-out values landing inside the 95% band.

+11%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 →
5.2Projected 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 →
2.5–7.995% 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 →
±45.8%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 rise about 11% by 2029 — from 4.7 in 2024 to a central estimate of 5.2 (95% range 2.5–7.9). A 5-year backtest shows a typical error of ±45.8%, 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 →
20255.02.47.7
20265.12.47.8
20275.12.57.8
20285.22.57.9
20295.22.57.9

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 →
Hill Creek5719951993
Aneth4320241996
La Sal 22720062003
Bonanza2620151992
Wellington2520021997
Monticello2420241998
Moquith Mtn1920241987
Main Canyon1920241987
La Sal 31920242007
La Sal1720001996
Altonah1520151970
Moab1520241986
Newcastle1520221997
Wellington 31420242012
Fayette1420211993
Hatch1420241994
Book Ridge1420242003
Crawford Mts1320152015
Wellington 21320112003
Navajo Lake1020241969
Lynn1020231986
Ant Flat-Ogden Can1020211994
Richfield1020191994
Fish Lake Nf920241993
Blanding920241992

Spotted Towhee Population Trend in Other States

arizonacaliforniacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexaswashingtonwyoming

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