BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Yellow-headed Blackbird In Coastal California

All regionsCoastal CaliforniaGeneralists

Yellow-headed Blackbird in Coastal California has collapsed: down 98% on the route-weighted index since 1970.

-98%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 →
27Routes 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 →
47YearsYears 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 declinecomputed 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 →

Yellow-headed Blackbird has collapsed in Coastal California: down 98% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Yellow-headed Blackbird in Coastal California is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±1277.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.00Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.395% 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 →
±1277.9%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, Yellow-headed Blackbird in Coastal California is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±1277.9%, with 100% of held-out values landing inside the 95% band.19682028
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 →
20240.000.001.3
20250.000.001.3
20260.000.001.3
20270.000.001.3
20280.000.001.3

Routes In Coastal California

Routes recording Yellow-headed Blackbird 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 →
ArvinCALIFORNIA382015
Anza 2CALIFORNIA322005
Oak GroveCALIFORNIA251984
Ora LomaCALIFORNIA211983
Elizabeth LkCALIFORNIA71986
MaricopaCALIFORNIA41977
WestleyCALIFORNIA41996
Buena VistaCALIFORNIA42019
TranquillityCALIFORNIA31998
MorenoCALIFORNIA21979
GlennCALIFORNIA22006
PenningtonCALIFORNIA11995
GravesboroCALIFORNIA11995
BakersfieldCALIFORNIA12017
HollisterCALIFORNIA12001
Orange CoveCALIFORNIA11978
OrlandCALIFORNIA11983
OnoCALIFORNIA11995
Lake HemetCALIFORNIA11986
AnzaCALIFORNIA11984
Carrizo PlnCALIFORNIA12013
ShafterCALIFORNIA11988
AtwaterCALIFORNIA12012
ZamoraCALIFORNIA12009
OnealsCALIFORNIA12011

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