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

European Starling In Coastal California

All regionsCoastal CaliforniaGeneralists

European Starling in Coastal California has risen sharply: up 51% on the route-weighted index since 1970.

+51%Since 1970TrendPercent 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 →
121Routes 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 →
57YearsYears 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

European Starling has risen sharply in Coastal California: up 51% on the route-weighted index since 1970.

European Starling In Coastal California Population Forecast

If the recent trend holds, European Starling in Coastal California is projected to stay roughly flat through 2030, near 47 (95% range 25–68). A 5-year backtest shows a typical error of ±36.7%, with 80% of held-out values landing inside the 95% band.

+0%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 →
47Projected 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 →
25–6895% 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 →
±36.7%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, European Starling in Coastal California is projected to stay roughly flat through 2030, near 47 (95% range 25–68). A 5-year backtest shows a typical error of ±36.7%, 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 →
2026472669
2027472669
2028472669
2029472669
2030472568

Routes In Coastal California

Routes recording European Starling 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 →
WestleyCALIFORNIA2852025
AthloneCALIFORNIA2812007
OrlandCALIFORNIA2622022
HollisterCALIFORNIA1812011
LivermoreCALIFORNIA1741991
Yolla BollyCALIFORNIA1732025
GravesboroCALIFORNIA1671995
CordovaCALIFORNIA1291981
ParkfieldCALIFORNIA1262025
Tres Pinos 2CALIFORNIA1252011
GreenfieldCALIFORNIA1042025
Collegeville 2CALIFORNIA1042023
Red BluffCALIFORNIA1012025
GlennCALIFORNIA1002025
Santa Cruz ICALIFORNIA951988
South LakeCALIFORNIA932006
CohassetCALIFORNIA902025
HughsonCALIFORNIA832025
TiptonCALIFORNIA821997
AtwaterCALIFORNIA812012
Tracy 2CALIFORNIA772024
Hollister 2CALIFORNIA752024
AuburnCALIFORNIA681980
VentucopaCALIFORNIA662002
SangerCALIFORNIA602024

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