BirdAnalyst
Guild · Wyoming · BBS 2026 Release · 1966–2025

Grassland Birds In Wyoming

All statesWyoming

17 species in this guild. As a group they are -62%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 1970.

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 fallen sharply in Wyoming, down 62% since 1970.

Grassland Birds In Wyoming Population Forecast

If the recent trend holds, Grassland birds in Wyoming is projected to fall about 43% by 2030 — from 9.8 in 2025 to a central estimate of 5.6 (95% range 0.00–13). A 5-year backtest shows a typical error of ±39.9%, with 100% of held-out values landing inside the 95% band.

-43%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 →
5.6Projected 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 →
0.00–1395% 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 →
±39.9%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 Wyoming is projected to fall about 43% by 2030 — from 9.8 in 2025 to a central estimate of 5.6 (95% range 0.00–13). A 5-year backtest shows a typical error of ±39.9%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20266.80.0014
20276.50.0014
20286.20.0014
20295.90.0013
20305.60.0013

Member Species In Wyoming

Grassland birds species in Wyoming.
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 →
Chestnut-collared LongspurCalcariidae-78%
Lark BuntingPasserellidae-73%
Clay-colored SparrowPasserellidae-63%
Baird's SparrowPasserellidae-40%
Horned LarkAlaudidae-39%
Western MeadowlarkIcteridae-25%
Lark SparrowPasserellidae-6%
Loggerhead ShrikeLaniidae+16%
Cassin's SparrowPasserellidae+23%
DickcisselCardinalidae+29%
Vesper SparrowPasserellidae+39%
American PipitMotacillidae+49%
Grasshopper SparrowPasserellidae+51%
Thick-billed LongspurCalcariidae+125%
BobolinkIcteridae+224%
Upland SandpiperScolopacidae+335%
Savannah SparrowPasserellidae+520%

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