BirdAnalyst
Species · Wyoming · BBS 2026 Release · 1966–2025

Black-billed Magpie Population Trend in Wyoming

All statesGeneralists

Black-billed Magpie in Wyoming has declined: down 36% on the route-weighted index since 1970.

-36%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 →
119Routes 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 WyomingNotable 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 Wyoming. See the full index history below.

Black-billed Magpie Population Forecast in Wyoming

If the recent trend holds, Black-billed Magpie in Wyoming is projected to fall about 23% by 2030 — from 5.7 in 2025 to a central estimate of 4.4 (95% range 0.00–10). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.

-23%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 →
4.4Projected 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 →
0.00–1095% 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 →
±49.1%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, Black-billed Magpie in Wyoming is projected to fall about 23% by 2030 — from 5.7 in 2025 to a central estimate of 4.4 (95% range 0.00–10). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20264.70.0010
20274.60.0010
20284.60.0010
20294.50.0010
20304.40.0010

Black-billed Magpie Survey Routes in Wyoming

Routes recording Black-billed Magpie in Wyoming.
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 →
Boulder9620251982
Carter6820162006
Green River4419841977
Meeteetse3720251991
Riverside3220251968
Cody2720251983
Lovell2720251989
Leo2320251982
Crowheart2220211987
Dayton2120251980
Sybille Cyn2020251980
Savery1719951989
Nowood1620251988
Ethete1620251991
Warbonnet1420242008
Dubois1320251968
Anchor1320181993
Wyarno1220251974
Fontenelle1220251982
Horse Creek1220251980
Carter 21220252017
Bucknum1120241993
Savery 21020252007
Ervay920251973
Glenrock919771968

Black-billed Magpie Population Trend in Other States

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