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

Pied-billed Grebe Population Trend in South Dakota

All statesWetland birds

Pied-billed Grebe in South Dakota has increased: up 26% on the route-weighted index since 1969.

+26%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 →
44Routes 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 Pied-billed Grebe 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 Pied-billed Grebe in South Dakota. See the full index history below.

Pied-billed Grebe Population Forecast in South Dakota

If the recent trend holds, Pied-billed Grebe in South Dakota is projected to rise about 87% by 2029 — from 0.46 in 2024 to a central estimate of 0.85 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±43.6%, with 100% of held-out values landing inside the 95% band.

+87%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 →
0.85Projected 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 →
0.00–1.995% 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 →
±43.6%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, Pied-billed Grebe in South Dakota is projected to rise about 87% by 2029 — from 0.46 in 2024 to a central estimate of 0.85 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±43.6%, 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 →
20250.850.001.9
20260.850.001.9
20270.850.001.9
20280.850.001.9
20290.850.001.9

Pied-billed Grebe Survey Routes in South Dakota

Routes recording Pied-billed Grebe 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 →
Geddes4319991997
White Lake1520111967
Roswell1520121967
Gettysburg1320231973
Broadland520121999
Britton520221969
Cottonwood420221992
Wilmot420241997
Lacreek420231991
Chamberlain319901990
Gorman320072007
Eagle Butte320152010
Marcus320102010
White River320111994
Pioneer220011992
Rockyford219741974
Raymond220191985
Crow Creek220232011
Forbes220241967
Long Lake220191969
Harding220121979
Fort Pierre220241971
Ardmore220191977
French Creek220021995
Lennox120221973

Pied-billed Grebe Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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