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

Violet-green Swallow Population Trend in South Dakota

All statesAerial insectivores

Violet-green Swallow in South Dakota has surged: up 76% on the route-weighted index since 1969.

+76%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 →
20Routes 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 Violet-green 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 →

Violet-green Swallow has surged in South Dakota: up 76% on the route-weighted index since 1969.

Violet-green Swallow Population Forecast in South Dakota

If the recent trend holds, Violet-green Swallow in South Dakota is projected to stay roughly flat through 2030, near 1.1 (95% range 0.30–2.0). A 5-year backtest shows a typical error of ±163%, with 40% of held-out values landing inside the 95% band.

-8%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 →
1.1Projected 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 →
0.30–2.095% 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 →
±163%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, Violet-green Swallow in South Dakota is projected to stay roughly flat through 2030, near 1.1 (95% range 0.30–2.0). A 5-year backtest shows a typical error of ±163%, with 40% 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 →
20261.10.272.0
20271.10.272.0
20281.10.282.0
20291.10.292.0
20301.10.302.0

Violet-green Swallow Survey Routes in South Dakota

Routes recording Violet-green 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 →
Roubaix Lk2519911967
Badlands1420252025
Pleasant Val1420181994
Long Draw1220251993
Reva1020241987
Lightning Cr620221992
Black Fox520171994
Norbeck520011992
Custer420251967
Hazelrodt420251992
Owanka319991999
Rochford320141992
Englewood220181992
Elk Mountain220001992
Silver City220121992
S. Pioneer120232023
Wind Cave Np120232003
Cedar Pass120252025
Ardmore120132013
Hill City120131994

Violet-green Swallow Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomontananebraskanevadanew-mexiconorth-dakotaoregontexasutahwashingtonwyoming

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