BirdAnalyst
Species · BCR 32 · BBS 2026 Release · 1966–2025

American Barn Owl In Coastal California

All regionsCoastal CaliforniaBirds of prey

American Barn Owl in Coastal California has declined: down 28% on the route-weighted index since 1972.

-28%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 →
48Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Coastal California. See the full index history below.

American Barn Owl In Coastal California Population Forecast

If the recent trend holds, American Barn Owl in Coastal California is projected to fall about 70% by 2030 — from 0.16 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±62.8%, with 80% of held-out values landing inside the 95% band.

-70%Change by 2030TrendPercent 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 →
0.05Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1395% 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 →
±62.8%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 Coastal California is projected to fall about 70% by 2030 — from 0.16 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±62.8%, with 80% of held-out values landing inside the 95% band.19682030
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 →
20260.050.000.14
20270.050.000.14
20280.050.000.13
20290.050.000.13
20300.050.000.13

Routes In Coastal California

Routes recording American Barn Owl in Coastal 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 →
AdelaidaCALIFORNIA52025
MoragaCALIFORNIA42005
WestleyCALIFORNIA21977
OnealsCALIFORNIA22016
LivermoreCALIFORNIA21979
TracyCALIFORNIA22004
Tracy 2CALIFORNIA22017
Red BluffCALIFORNIA11977
PenningtonCALIFORNIA11990
RumseyCALIFORNIA11975
RiovistaCALIFORNIA12011
CollegevilleCALIFORNIA11998
HughsonCALIFORNIA12023
Tres PinosCALIFORNIA11981
GravesboroCALIFORNIA11986
ParkfieldCALIFORNIA11975
BakersfieldCALIFORNIA11999
Santa YnezCALIFORNIA11994
Oak GroveCALIFORNIA12018
San YsidroCALIFORNIA11989
HollisterCALIFORNIA12011
Orange CoveCALIFORNIA11993
Lake SuccessCALIFORNIA11980
Morro BayCALIFORNIA11993
Point ReyesCALIFORNIA12012

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.