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

White-throated Swift Population Trend in Montana

All statesAerial insectivores

White-throated Swift in Montana has surged: up 179% on the route-weighted index since 1973.

+179%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 →
32YearsYears 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 179% 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 rise about 80% by 2029 — from 0.22 in 2024 to a central estimate of 0.40 (95% range 0.01–0.80). A 5-year backtest shows a typical error of ±170.4%, with 100% of held-out values landing inside the 95% band.

+80%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 →
0.40Projected 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 →
0.01–0.8095% 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 →
±170.4%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 rise about 80% by 2029 — from 0.22 in 2024 to a central estimate of 0.40 (95% range 0.01–0.80). A 5-year backtest shows a typical error of ±170.4%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.380.000.78
20260.390.000.78
20270.390.000.79
20280.400.000.80
20290.400.010.80

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 →
Bull Mtn.1420092008
Lima1320242001
Cramer Creek1220162010
Willow Creek1019801972
St Regis520181994
Fort Logan320232023
Arlee319691969
Pryor Mtn.320242001
Pagil Gulch220242015
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 2026-05-22.