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Species · California · BBS 2026 Release · 1966–2025

Red-winged Blackbird Population Trend in California

All statesWetland birds

Red-winged Blackbird in California has edged up: up 11% on the route-weighted index since 1970.

+11%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 →
214Routes In StateSurvey 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 Red-winged Blackbird Trends in CaliforniaNotable 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 California. See the full index history below.

Red-winged Blackbird Population Forecast in California

If the recent trend holds, Red-winged Blackbird in California is projected to fall about 30% by 2030 — from 60 in 2025 to a central estimate of 42 (95% range 2.4–83). A 5-year backtest shows a typical error of ±27.4%, with 100% of held-out values landing inside the 95% band.

-30%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 →
42Projected 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 →
2.4–8395% 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 →
±27.4%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 California is projected to fall about 30% by 2030 — from 60 in 2025 to a central estimate of 42 (95% range 2.4–83). A 5-year backtest shows a typical error of ±27.4%, 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 →
2026455.385
2027454.685
2028443.984
2029433.283
2030422.483

Red-winged Blackbird Survey Routes in California

Routes recording Red-winged Blackbird in 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 →
Dorris195220191972
Brawley144320121971
Glenn110220251971
Palo Verde78520251973
Niland77020251973
Likely48520251971
Imperial Dam36320101973
Athlone35620071973
Atwater34320121972
Buena Vista30320191990
Tres Pinos26620031968
Collegeville 226520232007
Cedarville24320251974
Paxton23620251998
Staten Is.22020251994
Alamo River21520181973
Riovista15620251968
Moreno15620251968
Jofegan15220232006
Hollister14620111973
Livermore14619911972
Ora Loma14320251972
Redding11919831972
Zamora11820251972
Iron Gate11420191988

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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