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

Wood Duck Population Trend in South Dakota

All statesWaterfowl

Wood Duck in South Dakota has surged: up 115% on the route-weighted index since 1971.

+115%Since 1971TrendPercent 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wood Duck 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Wood Duck has surged in South Dakota: up 115% on the route-weighted index since 1971.

Wood Duck Population Forecast in South Dakota

If the recent trend holds, Wood Duck in South Dakota is projected to fall about 32% by 2029 — from 0.50 in 2024 to a central estimate of 0.34 (95% range 0.02–0.65). A 5-year backtest shows a typical error of ±31.5%, with 100% of held-out values landing inside the 95% band.

-32%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 →
0.34Projected 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 →
0.02–0.6595% 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 →
±31.5%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, Wood Duck in South Dakota is projected to fall about 32% by 2029 — from 0.50 in 2024 to a central estimate of 0.34 (95% range 0.02–0.65). A 5-year backtest shows a typical error of ±31.5%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.330.020.65
20260.330.020.65
20270.340.020.65
20280.340.020.65
20290.340.020.65

Wood Duck Survey Routes in South Dakota

Routes recording Wood Duck 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 →
Ardmore920161994
Howard420221993
Cottonwood420062006
Winner420212008
Wilmot420241969
Forbes420241980
Lennox320141983
Volga320241973
Railroad Butte319981998
Veblen320231984
Owanka319881988
Broadland220102010
Indian220132004
Crow Creek220112011
Gettysburg219961993
Long Lake220191987
Maurine220171999
Tripp120231988
White Lake120111987
Geddes120171988
Raymond120181984
Roswell120121974
Britton120081973
French Creek120011996
Promise120101973

Wood Duck Population Trend in Other States

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

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