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

Eared Grebe Population Trend in South Dakota

All statesWetland birds

Eared Grebe in South Dakota has surged: up 24× on the route-weighted index since 1971.

24×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 →
15Routes 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 →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eared 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 →

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 →

Eared Grebe has surged in South Dakota: up 24× on the route-weighted index since 1971.

Eared Grebe Population Forecast in South Dakota

If the recent trend holds, Eared Grebe in South Dakota is projected to fall about 58% by 2029 — from 1.9 in 2024 to a central estimate of 0.78 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±424.2%, with 100% of held-out values landing inside the 95% band.

-58%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 →
0.78Projected 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 →
0.00–2.495% 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 →
±424.2%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, Eared Grebe in South Dakota is projected to fall about 58% by 2029 — from 1.9 in 2024 to a central estimate of 0.78 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±424.2%, 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 →
20250.760.002.4
20260.770.002.4
20270.770.002.4
20280.770.002.4
20290.780.002.4

Eared Grebe Survey Routes in South Dakota

Routes recording Eared 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 →
Cottonwood2720241992
S. Pioneer1420241995
White Lake520111967
Volga419911985
Harding319861977
Pioneer219931993
Ardmore219941978
Britton220021980
Cedar Pass119881967
Maurine120082008
Geddes119681968
Lodgepole120141997
White River120112009
Conde119841984
Long Lake120191971

Eared Grebe Population Trend in Other States

arizonacaliforniacoloradoidahoiowakansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregontexasutahwashingtonwyoming

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