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

Spotted Owl Population Trend in California

All statesGeneralists

Spotted Owl in California has fallen sharply: down 62% on the route-weighted index since 1975.

-62%Since 1975TrendPercent 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 →
17Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Spotted Owl 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 Spotted Owl in California. See the full index history below.

Spotted Owl Population Forecast in California

If the recent trend holds, Spotted Owl in California is projected to stay roughly flat through 2019, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±59.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2019TrendPercent 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 →
0.01Projected 2019 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0295% 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 →
±59.2%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, Spotted Owl in California is projected to stay roughly flat through 2019, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±59.2%, with 100% of held-out values landing inside the 95% band.19712019
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 →
20150.010.000.02
20160.010.000.02
20170.010.000.02
20180.010.000.02
20190.010.000.02

Spotted Owl Survey Routes in California

Routes recording Spotted Owl 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 →
Ship Mtn.219971997
Cottage Spgs219751975
Fallsvale219811981
Downieville119871987
Pollock Pines119991999
Honeydew119971997
Point Reyes119921992
Tujunga119921992
Bartle119741974
Glen Ellen119961986
Shasta Lake119871987
Greenhorn Mt119971971
Silver City120091978
Orange Cove119821982
Morro Bay119811981
Cleveland Nf120142014
Lumberyard119891989

Spotted Owl Population Trend in Other States

arizonaoregonwashington

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