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Species · California · BBS 2026 Release · 1966–2025

California Scrub-Jay Population Trend in California

All statesForest birds

California Scrub-Jay in California has edged down: down 18% on the route-weighted index since 1970.

-18%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 →
201Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable California Scrub-Jay 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 California Scrub-Jay in California. See the full index history below.

California Scrub-Jay Population Forecast in California

If the recent trend holds, California Scrub-Jay in California is projected to stay roughly flat through 2030, near 9.6 (95% range 7.1–12). A 5-year backtest shows a typical error of ±4%, with 100% of held-out values landing inside the 95% band.

-6%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 →
9.6Projected 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 →
7.1–1295% 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 →
±4%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, California Scrub-Jay in California is projected to stay roughly flat through 2030, near 9.6 (95% range 7.1–12). A 5-year backtest shows a typical error of ±4%, 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 →
20269.87.312
20279.77.312
20289.77.212
20299.67.112
20309.67.112

California Scrub-Jay Survey Routes in California

Routes recording California Scrub-Jay 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 →
Colma11519721968
Auburn7319801969
Jacumba6220251973
Gravesboro6119951968
White River6119921972
Lake Berryessa5520252023
Sisquoc5320141970
Cuyamaca Pk5320251970
Coyote5220251972
Lake Cachuma4820161972
Tres Pinos 24620112005
Kernville4420082008
Mt Laguna4319871970
Rumsey4220081969
Santa Ynez4020191969
Coalinga4020221973
Silver City3920131972
Lockwood Val3920191970
Greenfield3920251973
Lockwood3820251972
Alderpoint3820121974
Anza3520041970
Mesa Grande3420251970
Elsinore Mtn3420251970
Anza 23420252005

California Scrub-Jay Population Trend in Other States

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