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

White-throated Swift Population Trend in Washington

All statesAerial insectivores

White-throated Swift in Washington has surged: up 419% on the route-weighted index since 1984.

+419%Since 1984TrendPercent 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 →
12Routes 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 →
40YearsYears 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 WashingtonNotable 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 Washington: up 419% on the route-weighted index since 1984.

White-throated Swift Population Forecast in Washington

If the recent trend holds, White-throated Swift in Washington is projected to fall about 67% by 2030 — from 3.6 in 2025 to a central estimate of 1.2 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±148.7%, with 80% of held-out values landing inside the 95% band.

-67%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 →
1.2Projected 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 →
0.00–2.795% 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 →
±148.7%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 Washington is projected to fall about 67% by 2030 — from 3.6 in 2025 to a central estimate of 1.2 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±148.7%, with 80% of held-out values landing inside the 95% band.19822030
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 →
20261.10.002.7
20271.20.002.7
20281.20.002.7
20291.20.002.7
20301.20.002.7

White-throated Swift Survey Routes in Washington

Routes recording White-throated Swift in Washington.
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 →
Moses Coulee17420251993
Harrington620122012
Curlew620132005
Lake Chelan420021990
Snowden419941994
Winthrop419831983
Ellensburg319841984
Yakima320041993
Rimrock220191984
Selah120022002
Ardenvoir119821982
Reardan120132002

White-throated Swift Population Trend in Other States

arizonacaliforniacoloradoidahomontananebraskanevadanew-mexicooregonsouth-dakotatexasutahwyoming

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