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Species · Montana · BBS 2026 Release · 1966–2025

Savannah Sparrow Population Trend in Montana

All statesGrassland birds

Savannah Sparrow in Montana has surged: up 333% on the route-weighted index since 1970.

+333%Since 1970TrendPercent 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 →
99Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Savannah Sparrow Trends in MontanaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed 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 →

Savannah Sparrow has surged in Montana: up 333% on the route-weighted index since 1970.

Savannah Sparrow Population Forecast in Montana

If the recent trend holds, Savannah Sparrow in Montana is projected to rise about 37% by 2030 — from 12 in 2025 to a central estimate of 16 (95% range 10–22). A 5-year backtest shows a typical error of ±42.2%, with 80% of held-out values landing inside the 95% band.

+37%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 →
16Projected 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 →
10–2295% 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 →
±42.2%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, Savannah Sparrow in Montana is projected to rise about 37% by 2030 — from 12 in 2025 to a central estimate of 16 (95% range 10–22). A 5-year backtest shows a typical error of ±42.2%, 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 →
2026159.521
2027169.721
2028169.822
2029161022
2030161022

Savannah Sparrow Survey Routes in Montana

Routes recording Savannah Sparrow in Montana.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Pablo Res.10420251995
Beaverhead8920251973
Sunburst7920071971
Augusta7520251976
Chestnut4620251968
Raynesford4520252016
St Mary4420081968
Red Rock4420251975
Willow Creek 24120251982
Westby4120252015
Two Dot3120251976
Virgelle2820251979
Kalispell2720251968
Shelby2720252015
Redstone2620251968
Church Hill2520252017
Twin Bridges2419761968
Whitlash2420242009
Wolf Creek2120252015
Freeman Creek2120162015
Fort Logan1920252018
Boulder1820251969
Sula1720241977
Hebgen Lake1620252017
Polson1520251972

Savannah Sparrow Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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