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

Grassland Birds In South Dakota

All statesSouth Dakota

17 species in this guild. As a group they are -45%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1969.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Grassland birds as a group have declined in South Dakota, down 45% since 1969.

Grassland Birds In South Dakota Population Forecast

If the recent trend holds, Grassland birds in South Dakota is projected to fall about 39% by 2029 — from 21 in 2024 to a central estimate of 13 (95% range 5.3–21). A 5-year backtest shows a typical error of ±22.1%, with 80% of held-out values landing inside the 95% band.

-39%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 →
13Projected 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 →
5.3–2195% 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 →
±22.1%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, Grassland birds in South Dakota is projected to fall about 39% by 2029 — from 21 in 2024 to a central estimate of 13 (95% range 5.3–21). A 5-year backtest shows a typical error of ±22.1%, with 80% 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 →
2025146.522
2026146.221
2027145.921
2028135.621
2029135.321

Member Species In South Dakota

Grassland birds species in South Dakota.
TrendPercent 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 →
Eastern MeadowlarkIcteridae-92%
Lark BuntingPasserellidae-83%
Horned LarkAlaudidae-72%
Northern BobwhiteOdontophoridae-62%
Sprague's PipitMotacillidae-58%
DickcisselCardinalidae-34%
Baird's SparrowPasserellidae-29%
Western MeadowlarkIcteridae-28%
Vesper SparrowPasserellidae-25%
Savannah SparrowPasserellidae-21%
Grasshopper SparrowPasserellidae-13%
Ring-necked PheasantPhasianidae-11%
Lark SparrowPasserellidae+12%
BobolinkIcteridae+34%
Upland SandpiperScolopacidae+40%
Greater Prairie-ChickenPhasianidae+759%
Sedge WrenTroglodytidae11×

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