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

American Barn Owl Population Trend in California

All statesGeneralists

American Barn Owl in California has declined: down 45% on the route-weighted index since 1972.

-45%Since 1972TrendPercent 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 →
64Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Barn 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 American Barn Owl in California. See the full index history below.

American Barn Owl Population Forecast in California

If the recent trend holds, American Barn Owl in California is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±60.1%, 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 →
0.02Projected 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 →
0.00–0.0795% 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 →
±60.1%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, American Barn Owl in California is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±60.1%, 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 →
20250.020.000.07
20260.020.000.07
20270.020.000.07
20280.020.000.07
20290.020.000.07

American Barn Owl Survey Routes in California

Routes recording American Barn 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 →
Moraga420051979
Nubieber320122002
Coachella Cn320002000
Westley219771977
Onyx219931993
Tracy220041994
Oneals220161978
Livermore219791979
Tracy 2220172011
Adelaida220212015
Kelso Valley119941994
Elizabeth Lk120131975
Gazelle120112004
Red Bluff119771977
Lake Cachuma119871987
Jacumba119941986
Creston120061975
Pennington119901990
Carrizo Pln119921992
Rumsey119751975
Riovista120111999
Collegeville119981977
Hughson120231982
Likely120152014
Tres Pinos119811968

American Barn Owl Population Trend in Other States

alabamaarizonaarkansascoloradodelawarefloridageorgiaidahokansaskentuckylouisianamarylandmississippimissourinebraskanevadanew-mexiconorth-carolinaoklahomaoregonsouth-dakotatennesseetexasutahwashingtonwyoming

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