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

Cliff Swallow Population Trend in South Dakota

All statesAerial insectivores

Cliff Swallow in South Dakota has risen sharply: up 55% on the route-weighted index since 1969.

+55%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 →
60Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cliff Swallow 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 →

Cliff Swallow has risen sharply in South Dakota: up 55% on the route-weighted index since 1969.

Cliff Swallow Population Forecast in South Dakota

If the recent trend holds, Cliff Swallow in South Dakota is projected to fall about 37% by 2030 — from 68 in 2025 to a central estimate of 43 (95% range 15–70). A 5-year backtest shows a typical error of ±42.4%, with 20% of held-out values landing inside the 95% band.

-37%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 →
43Projected 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 →
15–7095% 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 →
±42.4%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, Cliff Swallow in South Dakota is projected to fall about 37% by 2030 — from 68 in 2025 to a central estimate of 43 (95% range 15–70). A 5-year backtest shows a typical error of ±42.4%, with 20% 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 →
2026411468
2027421469
2028421569
2029421569
2030431570

Cliff Swallow Survey Routes in South Dakota

Routes recording Cliff Swallow 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 →
Rockyford62820251967
Badlands37220251982
Cedar Pass16420251967
Geddes16120231971
Volunteer14920251967
Tripp13720251967
Ft Thompson10620111968
Chamberlain9020111969
Forbes8420251967
Conde6819841967
Custer6720251968
Marcus6320141999
Wilmot6220251967
Roswell5920121968
Maurine5720251968
Veblen5520231968
Lacreek5120251991
Howard5020251971
Reva4420251979
White River4120141994
Wind Cave Np4020222002
Britton3420231975
Lane 23120142000
White Lake2320111977
Isabel2320151990

Cliff Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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