BirdAnalyst
Guild · South Dakota · BBS 2026 Release · 1966–2025

Grassland Birds In South Dakota

All statesSouth Dakota

17 species in this guild. As a group they are -41%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 41% since 1969.

Grassland Birds In South Dakota Population Forecast

If the recent trend holds, Grassland birds in South Dakota is projected to fall about 42% by 2030 — from 19 in 2025 to a central estimate of 11 (95% range 4.1–18). A 5-year backtest shows a typical error of ±30.4%, with 60% of held-out values landing inside the 95% band.

-42%Change by 2030TrendPercent 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 →
11Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
4.1–1895% 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 →
±30.4%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 42% by 2030 — from 19 in 2025 to a central estimate of 11 (95% range 4.1–18). A 5-year backtest shows a typical error of ±30.4%, with 60% of held-out values landing inside the 95% band.19672030
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 →
2026125.219
2027125.019
2028124.719
2029114.418
2030114.118

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 →
Lark BuntingPasserellidae-81%
Chestnut-collared LongspurCalcariidae-77%
Horned LarkAlaudidae-68%
Eastern MeadowlarkIcteridae-67%
Sprague's PipitMotacillidae-58%
DickcisselCardinalidae-41%
Loggerhead ShrikeLaniidae-37%
Vesper SparrowPasserellidae-29%
Baird's SparrowPasserellidae-29%
Western MeadowlarkIcteridae-20%
Savannah SparrowPasserellidae-20%
Grasshopper SparrowPasserellidae-15%
Lark SparrowPasserellidae+30%
Clay-colored SparrowPasserellidae+34%
BobolinkIcteridae+41%
Upland SandpiperScolopacidae+48%
Sedge WrenTroglodytidae11×

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.