BirdAnalyst
Species · South Dakota · BBS 2026 Release · 1966–2025

Red-winged Blackbird Population Trend in South Dakota

All statesWetland birds

Red-winged Blackbird in South Dakota has edged down: down 15% on the route-weighted index since 1969.

-15%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 →
65Routes 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 South DakotaNotable 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 South Dakota. See the full index history below.

Red-winged Blackbird Population Forecast in South Dakota

If the recent trend holds, Red-winged Blackbird in South Dakota is projected to fall about 39% by 2030 — from 126 in 2025 to a central estimate of 77 (95% range 39–116). A 5-year backtest shows a typical error of ±34.2%, with 40% of held-out values landing inside the 95% band.

-39%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 →
77Projected 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 →
39–11695% 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 →
±34.2%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 South Dakota is projected to fall about 39% by 2030 — from 126 in 2025 to a central estimate of 77 (95% range 39–116). A 5-year backtest shows a typical error of ±34.2%, with 40% of held-out values landing inside the 95% band.19672030
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 →
20267941118
20277940117
20287840117
20297839116
20307739116

Red-winged Blackbird Survey Routes in South Dakota

Routes recording Red-winged Blackbird in South Dakota.
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 →
Turton59020251985
Forbes54320251967
Roswell32320141967
Broadland28920171967
Cedar Pass23520251967
Howard22020251970
Conde21619841967
Lodgepole21620251990
Volunteer21220251967
Geddes19120251967
Lacreek18420251991
Long Lake18220191967
White Lake18120111967
Rockyford16420251967
Isabel15920151990
Volga15120251967
Wilmot14520251967
Eagle Butte14020151990
Gettysburg13520231969
Raymond13020211967
Lane 212720142000
Promise12420151971
Crow Creek12120231967
Harding11820251967
Hayes11820241989

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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