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

Common Grackle Population Trend in South Dakota

All statesGeneralists

Common Grackle in South Dakota has declined: down 48% on the route-weighted index since 1969.

-48%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 →
63Routes 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 Common Grackle 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 Common Grackle in South Dakota. See the full index history below.

Common Grackle Population Forecast in South Dakota

If the recent trend holds, Common Grackle in South Dakota is projected to fall about 44% by 2030 — from 35 in 2025 to a central estimate of 20 (95% range 0.00–64). A 5-year backtest shows a typical error of ±34.2%, with 100% of held-out values landing inside the 95% band.

-44%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 →
20Projected 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 →
0.00–6495% 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 →
±34.2%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, Common Grackle in South Dakota is projected to fall about 44% by 2030 — from 35 in 2025 to a central estimate of 20 (95% range 0.00–64). A 5-year backtest shows a typical error of ±34.2%, 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 →
2026230.0068
2027220.0067
2028210.0066
2029210.0065
2030200.0064

Common Grackle Survey Routes in South Dakota

Routes recording Common Grackle 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 →
Conde39219841967
Roswell30020141967
Isabel18120151990
Rockyford17820251968
Eagle Butte15820151990
Lacreek13120251991
Chamberlain13020111967
Ft Thompson12020111967
Gettysburg11520231969
Lane 210920142000
Promise10120151971
Lane9919991967
Lennox7820251967
White Lake7120111967
Veblen6920231967
Forbes6920251967
Cedar Pass6820251969
Volga6720251967
Tripp6620251967
Howard6120251970
Broadland5820171967
Britton5520231967
Crow Creek5220231967
Gorman5220101979
Rosebud4820111967

Common Grackle Population Trend in Other States

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

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