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

Rufous-crowned Sparrow Population Trend in Arizona

All statesGeneralists

Rufous-crowned Sparrow in Arizona has surged: up 297% on the route-weighted index since 1970.

+297%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 →
33Routes 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 Rufous-crowned Sparrow 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 →

Rufous-crowned Sparrow has surged in Arizona: up 297% on the route-weighted index since 1970.

Rufous-crowned Sparrow Population Forecast in Arizona

If the recent trend holds, Rufous-crowned Sparrow in Arizona is projected to fall about 15% by 2029 — from 1.4 in 2024 to a central estimate of 1.2 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±12.2%, with 100% of held-out values landing inside the 95% band.

-15%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 →
1.2Projected 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 →
0.00–3.895% 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 →
±12.2%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, Rufous-crowned Sparrow in Arizona is projected to fall about 15% by 2029 — from 1.4 in 2024 to a central estimate of 1.2 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±12.2%, 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 →
20251.30.003.9
20261.30.003.9
20271.30.003.9
20281.20.003.9
20291.20.003.8

Rufous-crowned Sparrow Survey Routes in Arizona

Routes recording Rufous-crowned Sparrow 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 →
Peña Blanca2120241975
Cutter1620141998
Wickenburg920232019
Portal820241976
Patagonia820241968
Redington820231993
Dragoon520091993
Bartlett Res520241992
Peach Spring520082005
Carr Mtn520241985
Forest Lakes320242019
Seligman320122012
Oatman220061992
Aztec Peak219781978
Pomerene220061976
Sunizona219971978
Sunizona 2220152001
Sprucedale220232009
House Rock119991999
Rucker120081993
Yampai119721972
Prescott120171974
San Simon120162001
Cutter 2120182015
Alamo Res.120231992

Rufous-crowned Sparrow Population Trend in Other States

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