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Species · Montana · BBS 2026 Release · 1966–2025

Barn Swallow Population Trend in Montana

All statesAerial insectivores

Barn Swallow in Montana has edged down: down 12% on the route-weighted index since 1970.

-12%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 →
103Routes 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 Barn Swallow 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 Barn Swallow in Montana. See the full index history below.

Barn Swallow Population Forecast in Montana

If the recent trend holds, Barn Swallow in Montana is projected to fall about 11% by 2030 — from 4.3 in 2025 to a central estimate of 3.9 (95% range 0.66–7.1). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.

-11%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 →
3.9Projected 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 →
0.66–7.195% 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 →
±15.5%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, Barn Swallow in Montana is projected to fall about 11% by 2030 — from 4.3 in 2025 to a central estimate of 3.9 (95% range 0.66–7.1). A 5-year backtest shows a typical error of ±15.5%, 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 →
20264.10.887.3
20274.00.827.3
20284.00.777.2
20293.90.717.2
20303.90.667.1

Barn Swallow Survey Routes in Montana

Routes recording Barn Swallow 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.4620251995
Winifred3720232023
Wolf Point3420242015
Glasgow3020251968
Harlem2820211968
Locate2820251981
St Xavier 22720232017
Powderville1720251968
Roy1620251988
Brandenberg1620251968
Gildford1220252015
Brusett1120241982
Coleman Coulee1120242017
Chestnut1020181968
Beaverhead1020251974
Jordan South920252016
Forsyth820231980
Twin Bridges819761968
St Xavier820111979
St. Mary 2820232009
Dinosaurs H.M.820252018
Cabin Creek820242018
Libby Dam720251979
Virgelle720251979
Savage720251969

Barn Swallow 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.