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

White-throated Swift Population Trend in Montana

All statesAerial insectivores

White-throated Swift in Montana has surged: up 419% on the route-weighted index since 1973.

+419%Since 1973TrendPercent 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 →
16Routes 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 →
33YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable White-throated Swift 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 →

White-throated Swift has surged in Montana: up 419% on the route-weighted index since 1973.

White-throated Swift Population Forecast in Montana

If the recent trend holds, White-throated Swift in Montana is projected to fall about 47% by 2030 — from 0.85 in 2025 to a central estimate of 0.46 (95% range 0.03–0.88). A 5-year backtest shows a typical error of ±70.3%, with 80% of held-out values landing inside the 95% band.

-47%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 →
0.46Projected 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 →
0.03–0.8895% 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 →
±70.3%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, White-throated Swift in Montana is projected to fall about 47% by 2030 — from 0.85 in 2025 to a central estimate of 0.46 (95% range 0.03–0.88). A 5-year backtest shows a typical error of ±70.3%, with 80% of held-out values landing inside the 95% band.19692030
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 →
20260.420.000.85
20270.430.010.86
20280.440.020.86
20290.450.020.87
20300.460.030.88

White-throated Swift Survey Routes in Montana

Routes recording White-throated Swift 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 →
Pryor Mtn.3120252001
Lima3020252001
Bull Mtn.1420092008
Cramer Creek1220162010
Pagil Gulch1020252015
Willow Creek1019801972
St Regis520181994
Fort Logan320232023
Arlee319691969
Victor220192013
Willow Creek 2220221991
Brandenberg220191993
Reed Point120102010
Polson120142014
Painted Rock120001992
Shawmut120242024

White-throated Swift Population Trend in Other States

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