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Species · California · BBS 2026 Release · 1966–2025

California Quail Population Trend in California

All statesGame birds

California Quail in California has edged up: up 21% on the route-weighted index since 1970.

+21%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 →
218Routes 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 Quail 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 Quail in California. See the full index history below.

California Quail Population Forecast in California

If the recent trend holds, California Quail in California is projected to fall about 22% by 2030 — from 13 in 2025 to a central estimate of 10 (95% range 6.0–15). A 5-year backtest shows a typical error of ±21.1%, with 80% of held-out values landing inside the 95% band.

-22%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 →
10Projected 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 →
6.0–1595% 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 →
±21.1%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 Quail in California is projected to fall about 22% by 2030 — from 13 in 2025 to a central estimate of 10 (95% range 6.0–15). A 5-year backtest shows a typical error of ±21.1%, with 80% 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 →
2026106.015
2027106.015
2028106.015
2029106.015
2030106.015

California Quail Survey Routes in California

Routes recording California Quail 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 →
S Catalina15220251988
Lake Berryessa9220252023
Adelaida7920251970
Coalinga7220221973
White River5619921972
Yolla Bolly5020251973
Tehama4920221973
Rumsey4720081969
Jacumba4720251973
Lockwood Val4520191970
Jackson4519921972
Dorris4120191972
Cedarville4120251974
Poway3519801973
Oak Grove3320251968
Colma3219721968
Greenfield3120251973
Sanger3020242011
Kelso Valley3020251973
Pearblossom2920251970
Tres Pinos 22920112005
Yokohl Val2819971972
Auburn2719801969
Cuyamaca Pk2720251970
Santa Cruz I2719881988

California Quail Population Trend in Other States

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