BirdAnalyst
Species · Wisconsin · BBS 2026 Release · 1966–2025

Red-winged Blackbird Population Trend in Wisconsin

All statesWetland birds

Red-winged Blackbird in Wisconsin has declined: down 34% on the route-weighted index since 1968.

-34%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 →
59YearsYears 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 15% by 2030 — from 87 in 2025 to a central estimate of 74 (95% range 46–103). A 5-year backtest shows a typical error of ±9.6%, with 100% of held-out values landing inside the 95% band.

-15%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 →
74Projected 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 →
46–10395% 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 →
±9.6%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 Wisconsin is projected to fall about 15% by 2030 — from 87 in 2025 to a central estimate of 74 (95% range 46–103). A 5-year backtest shows a typical error of ±9.6%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20268052108
20277950107
20287749106
20297648104
20307446103

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 Andover38620251967
Omro30520011966
Hazel Green29520251966
Beloit28520251998
Eden23220251966
Grimms22920211998
Stratford21020251966
Unity20320251967
Paris19720251966
Annaton19220251998
Trempealeau19020251966
Brownsville18020251966
Raymond17220251966
Gilman16520251966
Wiota16320251966
Pardeeville15920251967
Stetsonville15720251990
Mukwonago15620041998
Highland15520251998
Hudson14720251966
Kiel14620251998
Rolling Pr14520251966
Wis Rapids14420231966
Manitowoc13220241966
Mount Horeb12619901967

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 2026-08-14.