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

California Quail Population Trend in Oregon

All statesGeneralists

California Quail in Oregon has edged down: down 14% on the route-weighted index since 1970.

-14%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 →
105Routes 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 California Quail Trends in OregonNotable 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 Oregon. See the full index history below.

California Quail Population Forecast in Oregon

If the recent trend holds, California Quail in Oregon is projected to fall about 21% by 2029 — from 3.5 in 2024 to a central estimate of 2.8 (95% range 0.62–5.0). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.

-21%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 →
2.8Projected 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 →
0.62–5.095% 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 →
±19.3%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 Oregon is projected to fall about 21% by 2029 — from 3.5 in 2024 to a central estimate of 2.8 (95% range 0.62–5.0). A 5-year backtest shows a typical error of ±19.3%, 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 →
20252.90.705.0
20262.90.685.0
20272.80.665.0
20282.80.645.0
20292.80.625.0

California Quail Survey Routes in Oregon

Routes recording California Quail in Oregon.
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 →
Bowden Hills4519991999
Deschutes3420241968
Fandango Can3020241978
Umatilla2920231988
Ordnance2319791971
Pendleton2320241972
Fish Lake1820241972
Hash Rock1720241983
Green Mtn.1620241994
Trout Creek1520211996
Alvord Lake1320241968
Modoc Point 21320242024
Malheur Res.1320232022
Sparta1120011971
Mount Vernon1120241986
Madras1120241997
Warner Vally1120241993
Adair1020241971
Adrian1020211984
Malheur Nwr1020221987
Newbridge1020241992
Mcminnville1020241994
Sheaville1020242012
Scappoose1020231996
Derby919931968

California Quail Population Trend in Other States

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