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

White-throated Swift Population Trend in Idaho

All statesAerial insectivores

White-throated Swift in Idaho has risen sharply: up 63% on the route-weighted index since 1990.

+63%Since 1990TrendPercent 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 →
9Routes 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 →
31YearsYears 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 IdahoNotable 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 risen sharply in Idaho: up 63% on the route-weighted index since 1990.

White-throated Swift Population Forecast in Idaho

If the recent trend holds, White-throated Swift in Idaho is projected to fall about 51% by 2030 — from 0.40 in 2025 to a central estimate of 0.20 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±24.2%, with 80% of held-out values landing inside the 95% band.

-51%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 →
0.20Projected 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 →
0.00–0.4195% 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 →
±24.2%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 Idaho is projected to fall about 51% by 2030 — from 0.40 in 2025 to a central estimate of 0.20 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±24.2%, with 80% of held-out values landing inside the 95% band.19882030
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 →
20260.190.000.40
20270.190.000.40
20280.190.000.40
20290.190.000.40
20300.200.000.41

White-throated Swift Survey Routes in Idaho

Routes recording White-throated Swift in Idaho.
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 →
Almo720251988
Magic Mtn520251988
Mora420222019
Leadore320102010
Salmon River220231988
Hot Spring120251995
Sunbeam120252007
Featherville119921992
Dougal Res119921989

White-throated Swift Population Trend in Other States

arizonacaliforniacoloradomontananebraskanevadanew-mexicooregonsouth-dakotatexasutahwashingtonwyoming

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