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

Red-winged Blackbird In Coastal California

All regionsCoastal CaliforniaWetland birds

Red-winged Blackbird in Coastal California has declined: down 38% on the route-weighted index since 1970.

-38%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 →
115Routes 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 Red-winged Blackbird in Coastal California. See the full index history below.

Red-winged Blackbird In Coastal California Population Forecast

If the recent trend holds, Red-winged Blackbird in Coastal California is projected to fall about 34% by 2030 — from 60 in 2025 to a central estimate of 40 (95% range 0.00–94). A 5-year backtest shows a typical error of ±49.6%, with 100% of held-out values landing inside the 95% band.

-34%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 →
40Projected 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 →
0.00–9495% 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 →
±49.6%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, Red-winged Blackbird in Coastal California is projected to fall about 34% by 2030 — from 60 in 2025 to a central estimate of 40 (95% range 0.00–94). A 5-year backtest shows a typical error of ±49.6%, 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 →
2026440.0098
2027430.0097
2028420.0096
2029410.0095
2030400.0094

Routes In Coastal California

Routes recording Red-winged 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 →
GlennCALIFORNIA11022025
AthloneCALIFORNIA3562007
AtwaterCALIFORNIA3432012
Buena VistaCALIFORNIA3032019
Tres PinosCALIFORNIA2662003
Collegeville 2CALIFORNIA2652023
Staten Is.CALIFORNIA2202025
RiovistaCALIFORNIA1562025
MorenoCALIFORNIA1562025
JofeganCALIFORNIA1522023
HollisterCALIFORNIA1462011
LivermoreCALIFORNIA1461991
Ora LomaCALIFORNIA1432025
ReddingCALIFORNIA1191983
ZamoraCALIFORNIA1182025
CollegevilleCALIFORNIA1002004
TranquillityCALIFORNIA962024
OrlandCALIFORNIA922022
PowayCALIFORNIA751980
CaruthersCALIFORNIA731987
ShafterCALIFORNIA691989
ColmaCALIFORNIA581972
Hollister 2CALIFORNIA582024
PenningtonCALIFORNIA562025
RumseyCALIFORNIA562008

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