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

Short-eared Owl Population Trend in California

All statesGeneralists

Short-eared Owl in California has risen sharply: up 74% on the route-weighted index since 1974.

+74%Since 1974TrendPercent 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 →
15Routes 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 →
31YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Short-eared 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 Short-eared Owl in California. See the full index history below.

Short-eared Owl Population Forecast in California

If the recent trend holds, Short-eared Owl in California is projected to stay roughly flat through 2017, near 0.04 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±164.5%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2017TrendPercent 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 →
0.04Projected 2017 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1195% 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 →
±164.5%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, Short-eared Owl in California is projected to stay roughly flat through 2017, near 0.04 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±164.5%, with 100% of held-out values landing inside the 95% band.19722017
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 →
20130.040.000.11
20140.040.000.11
20150.040.000.11
20160.040.000.11
20170.040.000.11

Short-eared Owl Survey Routes in California

Routes recording Short-eared 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 →
Carrizo Pln1020111980
Parkfield119801980
Honey Lake120111972
Davis Creek119941972
Dorris120041972
Yreka119751975
Macdoel119981975
Alamo River119771977
Riovista119761976
Orland119741974
Clear Lk Res119731973
Cedarville120122012
Atwater120042004
Likely119991978
Lenwood119801980

Short-eared Owl Population Trend in Other States

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