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

Black-billed Magpie Population Trend in North Dakota

All statesGeneralists

Black-billed Magpie in North Dakota has declined: down 33% on the route-weighted index since 1969.

-33%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 →
57YearsYears 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 North 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 North Dakota. See the full index history below.

Black-billed Magpie Population Forecast in North Dakota

If the recent trend holds, Black-billed Magpie in North Dakota is projected to fall about 13% by 2029 — from 0.96 in 2024 to a central estimate of 0.83 (95% range 0.17–1.5). A 5-year backtest shows a typical error of ±25%, with 100% of held-out values landing inside the 95% band.

-13%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 →
0.83Projected 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 →
0.17–1.595% 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 →
±25%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 North Dakota is projected to fall about 13% by 2029 — from 0.96 in 2024 to a central estimate of 0.83 (95% range 0.17–1.5). A 5-year backtest shows a typical error of ±25%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.830.171.5
20260.830.171.5
20270.830.171.5
20280.830.171.5
20290.830.171.5

Black-billed Magpie Survey Routes in North Dakota

Routes recording Black-billed Magpie in North 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 →
Dickinson720241970
Turtle Mtns720241980
Solen720242005
Stanley620211967
Bentley520011996
Zap420241967
Carpio320231967
Denbigh320231968
Wild Rose320081985
Carson220011998
Emerado220181985
Rolla220221969
Niles220002000
Lark219811968
Roosevelt Pk220181982
Golva220231997
Glen Ullin220181992
Kempton120141984
Cooperstown120242001
Buchanan119891989
Bowesmont120101986
Nash120051995
Regan120211972
Ft Yates120041971
Dunn Center119921974

Black-billed Magpie Population Trend in Other States

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