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

House Sparrow Population Trend in Montana

All statesGeneralists

House Sparrow in Montana has increased: up 47% on the route-weighted index since 1970.

+47%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 →
76Routes 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 House 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 →

No notable trend signals for House Sparrow in Montana. See the full index history below.

House Sparrow Population Forecast in Montana

If the recent trend holds, House Sparrow in Montana is projected to fall about 12% by 2030 — from 9.6 in 2025 to a central estimate of 8.4 (95% range 4.2–13). A 5-year backtest shows a typical error of ±21.1%, with 80% of held-out values landing inside the 95% band.

-12%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 →
8.4Projected 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 →
4.2–1395% 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 →
±21.1%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, House Sparrow in Montana is projected to fall about 12% by 2030 — from 9.6 in 2025 to a central estimate of 8.4 (95% range 4.2–13). A 5-year backtest shows a typical error of ±21.1%, 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 →
20268.44.113
20278.44.213
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20298.44.213
20308.44.213

House Sparrow Survey Routes in Montana

Routes recording House 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.27420251995
Victor6520251993
Redstone6120251968
Harlem5920211968
Glentana5320252015
Great Falls4620251972
Kalispell3820251968
Jordan3320241970
Threemile Wa3320251993
Church Hill2620252017
Willow Creek2519811972
Boulder2220251969
Sun River2120252015
Winifred2020232023
Polson1920251988
Twin Bridges1919761968
Custer1920222019
Sunburst1620071968
Glasgow1620251968
Willow Creek 21320251982
Laurel1220221968
Hay Lake1120251988
Arlee1119871985
Westby1120252015
Clinton819791979

House Sparrow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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