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Species · California · BBS 2025 Release · 1966–2024

Western Screech-Owl Population Trend in California

All statesGeneralists

Western Screech-Owl in California has edged up: up 24% on the route-weighted index since 1973.

+24%Since 1973TrendPercent 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 →
54Routes 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Western Screech-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 Western Screech-Owl in California. See the full index history below.

Western Screech-Owl Population Forecast in California

If the recent trend holds, Western Screech-Owl in California is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±46.4%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.01Projected 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 →
0.00–0.0495% 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 →
±46.4%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, Western Screech-Owl in California is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±46.4%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.010.000.04
20260.010.000.04
20270.010.000.04
20280.010.000.04
20290.010.000.04

Western Screech-Owl Survey Routes in California

Routes recording Western Screech-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 →
Higgins Corn419971995
Woodfords219931993
Cal Hot Spgs220122012
Mesa Grande219951995
Adelaida219811974
Kelso Valley120231973
Nubieber119861986
Crescent Cty120051989
Honeydew120131976
Kings Canyon120242024
Red Bluff120172017
Lassen Park119881988
Lake Cachuma120132013
Gazelle119941994
Hullville119961996
Rumsey119851982
Gold Hill120232023
Burnt Ranch120162007
Longvale120131977
Redding119791979
Macdoel119761976
Mt Pinos119831969
Moraga120041987
Offield Mtn119801980
Glen Ellen 2120222022

Western Screech-Owl Population Trend in Other States

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