BirdAnalyst
Species · South Dakota · BBS 2026 Release · 1966–2025

White-throated Swift Population Trend in South Dakota

All statesAerial insectivores

White-throated Swift in South Dakota has surged: up 153% on the route-weighted index since 1969.

+153%Since 1969TrendPercent 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 →
15Routes 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 White-throated Swift Trends in South DakotaNotable 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 South Dakota: up 153% on the route-weighted index since 1969.

White-throated Swift Population Forecast in South Dakota

If the recent trend holds, White-throated Swift in South Dakota is projected to stay roughly flat through 2030, near 0.62 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±91.7%, with 100% of held-out values landing inside the 95% band.

+2%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 →
0.62Projected 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 →
0.00–1.495% 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 →
±91.7%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 South Dakota is projected to stay roughly flat through 2030, near 0.62 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±91.7%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.630.001.4
20270.630.001.4
20280.630.001.4
20290.620.001.4
20300.620.001.4

White-throated Swift Survey Routes in South Dakota

Routes recording White-throated Swift in South Dakota.
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 →
Hill City4219971997
Cedar Pass2019991969
Badlands920011990
Long Draw720251992
Elk Mountain720041996
Lightning Cr420251995
Reva320251979
Pleasant Val320061997
Wind Cave Np320252015
Rockyford220222022
Black Fox220031992
Custer219811979
Norbeck219951995
Hazelrodt120151992
Roubaix Lk119911967

White-throated Swift Population Trend in Other States

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