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

Black-billed Magpie Population Trend in South Dakota

All statesGeneralists

Black-billed Magpie in South Dakota has held roughly steady: down 3% on the route-weighted index since 1969.

-3%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 →
31Routes 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 Black-billed Magpie 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 Black-billed Magpie in South Dakota. See the full index history below.

Black-billed Magpie Population Forecast in South Dakota

If the recent trend holds, Black-billed Magpie in South Dakota is projected to fall about 87% by 2030 — from 1.1 in 2025 to a central estimate of 0.15 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±115.2%, with 0% of held-out values landing inside the 95% band.

-87%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 →
0.15Projected 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 →
0.00–1.295% 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 →
±115.2%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, Black-billed Magpie in South Dakota is projected to fall about 87% by 2030 — from 1.1 in 2025 to a central estimate of 0.15 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±115.2%, with 0% 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 →
20260.190.001.2
20270.180.001.2
20280.170.001.2
20290.160.001.2
20300.150.001.2

Black-billed Magpie Survey Routes in South Dakota

Routes recording Black-billed Magpie 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 →
Wind Cave Np1020251999
Badlands620251982
Owanka519761970
Reva520251979
White River420121997
Rosebud319731967
Rockyford320251967
Veblen319701970
Promise319741971
Englewood320212011
Hazelrodt320251997
Cottonwood220232018
Crow Creek219671967
Laplant219901971
Volunteer219671967
Custer219791967
Cedar Pass220251968
Rochford220251996
Chamberlain119781967
Winner120181968
French Creek120011995
Ft Thompson119741974
Roubaix Lk119901967
Harding119681968
Fort Pierre119951968

Black-billed Magpie Population Trend in Other States

alaskaarizonacaliforniacoloradoidahokansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonutahwashingtonwyoming

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