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

Indigo Bunting Population Trend in South Dakota

All statesGeneralists

Indigo Bunting in South Dakota has surged: up 106% on the route-weighted index since 1970.

+106%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 →
27Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Indigo Bunting 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 →

Indigo Bunting has surged in South Dakota: up 106% on the route-weighted index since 1970.

Indigo Bunting Population Forecast in South Dakota

If the recent trend holds, Indigo Bunting in South Dakota is projected to fall about 75% by 2029 — from 0.32 in 2024 to a central estimate of 0.08 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±57.1%, with 80% of held-out values landing inside the 95% band.

-75%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 →
0.00–0.2295% 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 →
±57.1%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, Indigo Bunting in South Dakota is projected to fall about 75% by 2029 — from 0.32 in 2024 to a central estimate of 0.08 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±57.1%, with 80% of held-out values landing inside the 95% band.19682029
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 →
20250.080.000.22
20260.080.000.22
20270.080.000.22
20280.080.000.22
20290.080.000.22

Indigo Bunting Survey Routes in South Dakota

Routes recording Indigo Bunting 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 →
Lennox220241979
Howard220241970
Chamberlain220111972
Rosebud220101972
Volga220242024
Eagle Butte220122010
Marcus220142014
Tripp120232015
White Lake119831983
Geddes119991993
Winner120212007
Rockyford119761968
Roswell120141974
Broadland120132013
Ft Thompson120111969
Wilmot120241971
Veblen120212004
Promise120121972
Roubaix Lk119821970
Volunteer119681968
Custer119751975
Fort Pierre119791979
Reva119941994
Hayes120172014
Lacreek119971997

Indigo Bunting Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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