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

Red-winged Blackbird Population Trend in Iowa

All statesGeneralists

Red-winged Blackbird in Iowa has held roughly steady: up 10% on the route-weighted index since 1969.

+10%Since 1969TrendPercent 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 →
39Routes 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 IowaNotable 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 Iowa. See the full index history below.

Red-winged Blackbird Population Forecast in Iowa

If the recent trend holds, Red-winged Blackbird in Iowa is projected to stay roughly flat through 2029, near 183 (95% range 153–212). A 5-year backtest shows a typical error of ±3.4%, with 100% of held-out values landing inside the 95% band.

+6%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 →
183Projected 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 →
153–21295% 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 →
±3.4%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 Iowa is projected to stay roughly flat through 2029, near 183 (95% range 153–212). A 5-year backtest shows a typical error of ±3.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
2025182152211
2026182153211
2027182153211
2028182153212
2029183153212

Red-winged Blackbird Survey Routes in Iowa

Routes recording Red-winged Blackbird in Iowa.
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 →
Cedar Valley36119971967
Davis Corner35620241968
Williamsburg32020231967
Brooklyn29620221967
Tipton26820241993
Bryant25520241967
West Liberty25320241968
Prairieburg25020241967
Mt Hamill24120241967
College Spgs21220041967
Hudson21020221967
Festina20220241968
Burchinal20220241995
Bedford18020181968
Red Rock17520241968
Melrose17120241974
Lafayette16320242003
Maquoketa16120241967
Scranton16120241967
Dinsdale15820241968
Garner15519931971
Wales15220181967
Rock Valley14420241968
College Spgs 214320232005
Zearing13519951967

Red-winged Blackbird Population Trend in Other States

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

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