BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Red-winged Blackbird Population Trend in Illinois

All statesGeneralists

Red-winged Blackbird in Illinois has edged down: down 25% on the route-weighted index since 1968.

-25%Since 1968TrendPercent 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 →
105Routes 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 →
58YearsYears 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 IllinoisNotable 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 Illinois. See the full index history below.

Red-winged Blackbird Population Forecast in Illinois

If the recent trend holds, Red-winged Blackbird in Illinois is projected to stay roughly flat through 2029, near 128 (95% range 78–178). A 5-year backtest shows a typical error of ±11.3%, with 100% of held-out values landing inside the 95% band.

+9%Change by 2029TrendPercent 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 →
128Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
78–17895% 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 →
±11.3%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 Illinois is projected to stay roughly flat through 2029, near 128 (95% range 78–178). A 5-year backtest shows a typical error of ±11.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
202513282182
202613181181
202713080180
202812979179
202912878178

Red-winged Blackbird Survey Routes in Illinois

Routes recording Red-winged Blackbird in Illinois.
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 →
Beaucoup43220241971
Pontiac33420241978
Streator27420241972
Newark26720221969
York26320241993
Geneseo25920211967
Guilford23920231967
Greenview22620241993
Harristown21920242001
Bradbury21020241970
Wayne20920241966
Pawnee20020241967
Essex19720241969
Sherrard19120241993
Jamestown18420241966
Troy Grove18420241993
Marshall18220242001
Lake Galena17720212001
Janesville17320241972
Sterling17020232001
Darmstadt16720241993
Stillwell15720241971
Buda15520231977
Yale15520241993
Fairdale15420242019

Red-winged Blackbird Population Trend in Other States

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

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