BirdAnalyst
Species · Montana · BBS 2025 Release · 1966–2024

House Sparrow Population Trend in Montana

All statesGeneralists

House Sparrow in Montana has risen sharply: up 52% on the route-weighted index since 1970.

+52%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 →
56YearsYears 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 →

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 →

House Sparrow has risen sharply in Montana: up 52% on the route-weighted index since 1970.

House Sparrow Population Forecast in Montana

If the recent trend holds, House Sparrow in Montana is projected to stay roughly flat through 2029, near 8.3 (95% range 4.1–13). A 5-year backtest shows a typical error of ±19.8%, with 80% of held-out values landing inside the 95% band.

+4%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 →
8.3Projected 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 →
4.1–1395% 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 →
±19.8%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 stay roughly flat through 2029, near 8.3 (95% range 4.1–13). A 5-year backtest shows a typical error of ±19.8%, with 80% of held-out values landing inside the 95% band.19682029
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 →
20258.34.013
20268.34.013
20278.34.013
20288.34.013
20298.34.113

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.11420241995
Victor8720241993
Harlem5920211968
Redstone5220241968
Polson4420241988
Great Falls4120241972
Church Hill4020242017
Sun River3920242015
Jordan3320241970
Glen3220241977
Willow Creek2519811972
Clyde Park2520242018
Willow Creek 22320241982
Hay Lake2120221988
Winifred2020232023
Twin Bridges1919761968
Custer1920222019
Sunburst1620071968
Glasgow1520241968
Boulder1420241969
Westby1320242015
Laurel1220221968
Arlee1119871985
Gildford1020242015
Threemile Wa920241993

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 2026-05-22.