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

Wetland Birds In South Dakota

All statesSouth Dakota

20 species in this guild. As a group they are -46%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 →

Wetland birds as a group have declined in South Dakota, down 46% since 1969.

Forecast

If the recent trend holds, Wetland birds in South Dakota is projected to stay roughly flat through 2029, near 0.72 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±52.4%, with 80% of held-out values landing inside the 95% band.

-6%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 →
0.72Projected 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 →
0.00–1.895% 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 →
±52.4%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, Wetland birds in South Dakota is projected to stay roughly flat through 2029, near 0.72 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±52.4%, 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 →
20250.760.001.8
20260.750.001.8
20270.740.001.8
20280.730.001.8
20290.720.001.8

Member Species In South Dakota

Wetland 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 →
Black-crowned Night HeronArdeidae-87%
Black TernLaridae-84%
American CootRallidae-71%
Western GrebePodicipedidae-67%
American White PelicanPelecanidae-46%
American BitternArdeidae-45%
Virginia RailRallidae-43%
California GullLaridae-34%
Forster's TernLaridae-21%
Franklin's GullLaridae-18%
Great Blue HeronArdeidae+2%
Double-crested CormorantPhalacrocoracidae+8%
Ring-billed GullLaridae+19%
Pied-billed GrebePodicipedidae+26%
Green HeronArdeidae+42%
SoraRallidae+60%
Western Cattle-EgretArdeidae+69%
Great EgretArdeidae+73%
White-faced IbisThreskiornithidae+105%
Eared GrebePodicipedidae24×

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