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

Grasshopper Sparrow Population Trend in South Dakota

All statesGrassland birds

Grasshopper Sparrow in South Dakota has edged down: down 13% on the route-weighted index since 1969.

-13%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 →
60Routes 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 Grasshopper Sparrow 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 Grasshopper Sparrow in South Dakota. See the full index history below.

Grasshopper Sparrow Population Forecast in South Dakota

If the recent trend holds, Grasshopper Sparrow in South Dakota is projected to fall about 25% by 2029 — from 20 in 2024 to a central estimate of 15 (95% range 5.1–25). A 5-year backtest shows a typical error of ±44.7%, with 100% of held-out values landing inside the 95% band.

-25%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 →
15Projected 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 →
5.1–2595% 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 →
±44.7%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, Grasshopper Sparrow in South Dakota is projected to fall about 25% by 2029 — from 20 in 2024 to a central estimate of 15 (95% range 5.1–25). A 5-year backtest shows a typical error of ±44.7%, 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 →
2025155.225
2026155.225
2027155.125
2028155.125
2029155.125

Grasshopper Sparrow Survey Routes in South Dakota

Routes recording Grasshopper Sparrow 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 →
Pioneer10820241992
Rosebud6620111967
Reva6320241979
Harding6220191969
S. Pioneer6020241994
Indian5120241994
Lodgepole4720241990
White River4420141994
Marcus4220151999
Crow Creek4020231967
Laplant4020151971
White Lake3620111967
Wind Cave Np3620241999
Promise3420151971
Ft Thompson3220111967
Owanka2920221967
Isabel2820151990
Maurine2520241968
Eagle Butte2520151990
Railroad Butte2420221995
Lane 22220142000
Chamberlain2020111967
Gettysburg2020231969
Ottumwa1820221967
Badlands1420231982

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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