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

Spotted Towhee Population Trend in Arizona

All statesGeneralists

Spotted Towhee in Arizona has surged: up 166% on the route-weighted index since 1970.

+166%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 →
41Routes 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 ArizonaNotable 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 Arizona: up 166% on the route-weighted index since 1970.

Spotted Towhee Population Forecast in Arizona

If the recent trend holds, Spotted Towhee in Arizona is projected to rise about 27% by 2029 — from 3.8 in 2024 to a central estimate of 4.8 (95% range 0.00–10). A 5-year backtest shows a typical error of ±20.3%, with 100% of held-out values landing inside the 95% band.

+27%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 →
4.8Projected 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 →
0.00–1095% 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 →
±20.3%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 Arizona is projected to rise about 27% by 2029 — from 3.8 in 2024 to a central estimate of 4.8 (95% range 0.00–10). A 5-year backtest shows a typical error of ±20.3%, 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 →
20254.90.0010
20264.90.0010
20274.90.0010
20284.90.0010
20294.80.0010

Spotted Towhee Survey Routes in Arizona

Routes recording Spotted Towhee in Arizona.
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 →
Prescott9420221974
Forest Lakes5020241992
Sprucedale4220231992
Tonto Vill.3520211992
Aztec Peak3219781974
Skull Valley3120241996
Portal2920241975
Mt. Graham2020231995
Dragoon1320091993
Carr Mtn1020241985
Pinetop920221993
Rucker820091993
Zeniff819841968
Tsaile820231993
Mt Trumbull719801980
Alpine720232009
Patagonia620241968
Williams620192001
Round Rock519721969
Blue419911974
Toroweap420211994
Cutter420001995
Peach Spring420221996
House Rock320221968
Black Mesa319951989

Spotted Towhee Population Trend in Other States

californiacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwyoming

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