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

Red-winged Blackbird Population Trend in Wisconsin

All statesGeneralists

Red-winged Blackbird in Wisconsin has declined: down 33% on the route-weighted index since 1968.

-33%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 →
98Routes 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 WisconsinNotable 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 Wisconsin. See the full index history below.

Red-winged Blackbird Population Forecast in Wisconsin

If the recent trend holds, Red-winged Blackbird in Wisconsin is projected to fall about 13% by 2029 — from 86 in 2024 to a central estimate of 75 (95% range 47–104). A 5-year backtest shows a typical error of ±10.1%, with 100% of held-out values landing inside the 95% band.

-13%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 →
75Projected 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 →
47–10495% 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 →
±10.1%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 Wisconsin is projected to fall about 13% by 2029 — from 86 in 2024 to a central estimate of 75 (95% range 47–104). A 5-year backtest shows a typical error of ±10.1%, 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 →
20258152109
20267951108
20277849106
20287748105
20297547104

Red-winged Blackbird Survey Routes in Wisconsin

Routes recording Red-winged Blackbird in Wisconsin.
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 →
N Andover31020241967
Omro30520011966
Hazel Green28220241966
Kiel27920221998
Beloit26820241998
Stratford23220241966
Grimms22920211998
Annaton21120241998
Eden20720241966
Paris20420241966
Raymond19720241966
Highland19720241998
Unity17620241967
Trempealeau17020241966
Stetsonville16820241990
Brownsville16620241966
Holland16020241998
Mukwonago15620041998
Pardeeville15020241967
Prairie Du Chien14720241998
Wis Rapids14420231966
Cochrane13720241966
Wiota13520241966
Rolling Pr13320241966
Manitowoc13220241966

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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