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

Grassland Birds In Montana

All statesMontana

16 species in this guild. As a group they are -5%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 →

No notable trend signals for grassland birds in Montana. See the full index history below.

Grassland Birds In Montana Population Forecast

If the recent trend holds, Grassland birds in Montana is projected to fall about 29% by 2030 — from 17 in 2025 to a central estimate of 12 (95% range 6.4–18). A 5-year backtest shows a typical error of ±21.7%, with 80% of held-out values landing inside the 95% band.

-29%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 →
12Projected 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 →
6.4–1895% 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 →
±21.7%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, Grassland birds in Montana is projected to fall about 29% by 2030 — from 17 in 2025 to a central estimate of 12 (95% range 6.4–18). A 5-year backtest shows a typical error of ±21.7%, with 80% 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 →
2026136.818
2027126.718
2028126.618
2029126.518
2030126.418

Member Species In Montana

Grassland birds species in Montana.
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-58%
Lark SparrowPasserellidae-51%
Loggerhead ShrikeLaniidae-18%
Western MeadowlarkIcteridae-10%
Horned LarkAlaudidae+3%
Baird's SparrowPasserellidae+51%
Vesper SparrowPasserellidae+73%
Chestnut-collared LongspurCalcariidae+76%
Sprague's PipitMotacillidae+107%
Clay-colored SparrowPasserellidae+123%
Thick-billed LongspurCalcariidae+290%
Savannah SparrowPasserellidae+333%
Grasshopper SparrowPasserellidae+503%
DickcisselCardinalidae+856%
BobolinkIcteridae+932%
Upland SandpiperScolopacidae13×

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