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Species · California · BBS 2026 Release · 1966–2025

Sagebrush Sparrow Population Trend in California

All statesArid-land birds

Sagebrush Sparrow in California has declined: down 43% on the route-weighted index since 1974.

-43%Since 1974TrendPercent 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 →
14Routes 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 →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Sagebrush Sparrow Trends in CaliforniaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Sagebrush Sparrow in California. See the full index history below.

Sagebrush Sparrow Population Forecast in California

If the recent trend holds, Sagebrush Sparrow in California is projected to fall about 79% by 2030 — from 0.26 in 2025 to a central estimate of 0.06 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±74.8%, with 80% of held-out values landing inside the 95% band.

-79%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 →
0.06Projected 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 →
0.00–0.2495% 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 →
±74.8%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, Sagebrush Sparrow in California is projected to fall about 79% by 2030 — from 0.26 in 2025 to a central estimate of 0.06 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±74.8%, with 80% of held-out values landing inside the 95% band.19722030
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 →
20260.060.000.25
20270.060.000.25
20280.060.000.25
20290.060.000.25
20300.060.000.24

Sagebrush Sparrow Survey Routes in California

Routes recording Sagebrush Sparrow in California.
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 →
Bartle3619771977
Honey Lake1320251972
Ravendale920251974
Ingalls320001985
Macdoel319771977
Mt Shasta319751975
Cedarville320011974
Davis Creek220011977
Dorris219761976
Lassen Park219811981
Clear Lk Res119971974
Tionesta120212012
Likely119791972
Madeline120022002

Sagebrush Sparrow Population Trend in Other States

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