BirdAnalyst
Species · South Dakota · BBS 2025 Release · 1966–2024

Green-winged Teal Population Trend in South Dakota

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Green-winged Teal in South Dakota has declined: down 33% on the route-weighted index since 1969.

-33%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 →
33Routes 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 →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Green-winged Teal 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 Green-winged Teal in South Dakota. See the full index history below.

Green-winged Teal Population Forecast in South Dakota

If the recent trend holds, Green-winged Teal in South Dakota is projected to fall about 77% by 2029 — from 0.41 in 2024 to a central estimate of 0.09 (95% range 0.00–0.75). A 5-year backtest shows a typical error of ±58.8%, with 100% of held-out values landing inside the 95% band.

-77%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 →
0.09Projected 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 →
0.00–0.7595% 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 →
±58.8%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, Green-winged Teal in South Dakota is projected to fall about 77% by 2029 — from 0.41 in 2024 to a central estimate of 0.09 (95% range 0.00–0.75). A 5-year backtest shows a typical error of ±58.8%, 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 →
20250.120.000.77
20260.110.000.77
20270.100.000.76
20280.100.000.76
20290.090.000.75

Green-winged Teal Survey Routes in South Dakota

Routes recording Green-winged Teal 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 →
Howard720241983
Gorman719801980
French Creek619961996
Gettysburg620191993
Britton520081969
Owanka419851967
Rockyford320102010
Lacreek320192019
Turton320092009
Geddes219881967
Winner220192019
Volga219901970
Veblen220221968
Forbes220231968
Long Lake220191967
Laplant220112011
Harding220171973
Fort Pierre220241971
Lennox120151973
White Lake120111969
Pioneer120001995
Cottonwood120091993
Raymond120121984
S. Pioneer120182012
Broadland120102007

Green-winged Teal Population Trend in Other States

alaskaarizonacaliforniacoloradoidahoillinoisindianaiowakansasmainemichiganminnesotamissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaoklahomaoregonpennsylvaniatexasutahvermontwashingtonwisconsinwyoming

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