BirdAnalyst
Species · South Dakota · BBS 2025 Release · 1966–2024

Chimney Swift Population Trend in South Dakota

All statesAerial insectivores

Chimney Swift in South Dakota has increased: up 48% on the route-weighted index since 1970.

+48%Since 1970TrendPercent 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 →
13Routes 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 →
46YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Chimney 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 →

No notable trend signals for Chimney Swift in South Dakota. See the full index history below.

Chimney Swift Population Forecast in South Dakota

If the recent trend holds, Chimney Swift in South Dakota is projected to fall about 55% by 2029 — from 0.18 in 2024 to a central estimate of 0.08 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±59.7%, with 100% of held-out values landing inside the 95% band.

-55%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 →
0.08Projected 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 →
0.00–0.3495% 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 →
±59.7%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, Chimney Swift in South Dakota is projected to fall about 55% by 2029 — from 0.18 in 2024 to a central estimate of 0.08 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±59.7%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.090.000.35
20260.090.000.35
20270.090.000.35
20280.080.000.34
20290.080.000.34

Chimney Swift Survey Routes in South Dakota

Routes recording Chimney 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 →
White Lake420001978
Broadland320011972
Forbes320242024
Tripp220161986
Crow Creek220112011
Veblen220192004
Lennox120171969
Howard120091971
Geddes120121988
Volga120181979
Roswell119981998
Wilmot120241967
Britton119831983

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.