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

American Coot Population Trend in South Dakota

All statesWetland birds

American Coot in South Dakota has fallen sharply: down 71% on the route-weighted index since 1969.

-71%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 →
46Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Coot 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 declinecomputed 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 →

American Coot has fallen sharply in South Dakota: down 71% on the route-weighted index since 1969.

American Coot Population Forecast in South Dakota

If the recent trend holds, American Coot in South Dakota is projected to fall about 48% by 2029 — from 2.0 in 2024 to a central estimate of 1.0 (95% range 0.00–5.9). A 5-year backtest shows a typical error of ±47.9%, with 100% of held-out values landing inside the 95% band.

-48%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 →
1.0Projected 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 →
0.00–5.995% 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 →
±47.9%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, American Coot in South Dakota is projected to fall about 48% by 2029 — from 2.0 in 2024 to a central estimate of 1.0 (95% range 0.00–5.9). A 5-year backtest shows a typical error of ±47.9%, 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 →
20251.30.006.1
20261.20.006.0
20271.10.006.0
20281.10.005.9
20291.00.005.9

American Coot Survey Routes in South Dakota

Routes recording American Coot 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 →
White Lake3520111967
Long Lake2620191967
S. Pioneer2520241994
White River2119981994
Broadland1920121970
Isabel1920152011
Gettysburg1720231969
Badlands1419971987
French Creek1220011997
Forbes1120241967
Lane 2720102007
Raymond620211968
Ardmore620191977
Roswell520141967
Crow Creek520192009
Veblen520221967
Gorman420071995
Britton320231967
Volunteer320191967
Ottumwa320191967
Howard220211983
Cottonwood220241992
Rockyford219741967
Ft Thompson219931967
Laplant219781971

American Coot Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutfloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamichiganminnesotamississippimissourimontananebraskanevadanew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniatennesseetexasutahvermontwashingtonwest-virginiawisconsinwyoming

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