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

Bullock's Oriole In Coastal California

All regionsCoastal CaliforniaForest birds

Bullock's Oriole in Coastal California has declined: down 33% on the route-weighted index since 1970.

-33%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 →
113Routes 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 →

No notable trend signals for Bullock's Oriole in Coastal California. See the full index history below.

Bullock's Oriole In Coastal California Population Forecast

If the recent trend holds, Bullock's Oriole in Coastal California is projected to stay roughly flat through 2030, near 4.5 (95% range 0.89–8.2). A 5-year backtest shows a typical error of ±47.2%, with 100% of held-out values landing inside the 95% band.

+4%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 →
4.5Projected 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 →
0.89–8.295% 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 →
±47.2%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, Bullock's Oriole in Coastal California is projected to stay roughly flat through 2030, near 4.5 (95% range 0.89–8.2). A 5-year backtest shows a typical error of ±47.2%, with 100% 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 →
20265.01.38.6
20274.91.28.5
20284.71.18.4
20294.61.008.3
20304.50.898.2

Routes In Coastal California

Routes recording Bullock's Oriole 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 →
White RiverCALIFORNIA331992
Yokohl ValCALIFORNIA251997
Tres Pinos 2CALIFORNIA232011
MorenoCALIFORNIA172025
AthloneCALIFORNIA162007
PowayCALIFORNIA151980
VentucopaCALIFORNIA152002
ParkfieldCALIFORNIA142025
Bartlett SpsCALIFORNIA142018
Cp. PendletonCALIFORNIA132003
Gold HillCALIFORNIA132025
Red BluffCALIFORNIA122025
OnoCALIFORNIA122011
RumseyCALIFORNIA112008
AuburnCALIFORNIA111980
FallsvaleCALIFORNIA111981
ReddingCALIFORNIA111983
PenningtonCALIFORNIA102025
Tres PinosCALIFORNIA102003
TiptonCALIFORNIA101996
BakersfieldCALIFORNIA92023
Lake SuccessCALIFORNIA91996
Mesa GrandeCALIFORNIA92025
SisquocCALIFORNIA92014
Harbor LakeCALIFORNIA81991

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