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Species · California · BBS 2025 Release · 1966–2024

Steller's Jay Population Trend in California

All statesGeneralists

Steller's Jay in California has held roughly steady: up 9% on the route-weighted index since 1970.

+9%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 →
164Routes 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 Steller's 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 Steller's Jay in California. See the full index history below.

Steller's Jay Population Forecast in California

If the recent trend holds, Steller's Jay in California is projected to rise about 72% by 2029 — from 6.4 in 2024 to a central estimate of 11 (95% range 6.9–15). A 5-year backtest shows a typical error of ±81%, with 0% of held-out values landing inside the 95% band.

+72%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 →
11Projected 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 →
6.9–1595% 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 →
±81%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, Steller's Jay in California is projected to rise about 72% by 2029 — from 6.4 in 2024 to a central estimate of 11 (95% range 6.9–15). A 5-year backtest shows a typical error of ±81%, with 0% 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 →
2025116.715
2026116.715
2027116.815
2028116.815
2029116.915

Steller's Jay Survey Routes in California

Routes recording Steller's 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 →
Dirigio6320141999
Ukiah4820111988
Fish Rock4620141968
Cecilville4620171999
Fallsvale4419811970
Navarro4020111972
Orleans 24020142014
Coyote3820241972
Carrville3619701970
Forest Hill3620221997
Whiskeytown3520132002
Burnt Ranch3520161998
Mt Pinos3420041969
Pescadero3320241992
Big Bear3119861969
Fairfax3020241972
Offield Mtn3020141973
Hat Creek3020181973
Friday Ridge3020241994
South Fork Mtn3020222000
Holmes2820241968
Green Valley2820231970
Mccloud2820211973
Last Chance2820191993
Bass Lake2720191972

Steller's Jay Population Trend in Other States

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