BirdAnalyst
Species · Wyoming · BBS 2025 Release · 1966–2024

Black-billed Magpie Population Trend in Wyoming

All statesGeneralists

Black-billed Magpie in Wyoming has declined: down 29% on the route-weighted index since 1970.

-29%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 →
118Routes 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 →
56YearsYears 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 45% by 2029 — from 8.0 in 2024 to a central estimate of 4.4 (95% range 0.00–10). A 5-year backtest shows a typical error of ±47.9%, with 100% of held-out values landing inside the 95% band.

-45%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 →
4.4Projected 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 →
0.00–1095% 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 →
±47.9%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 45% by 2029 — from 8.0 in 2024 to a central estimate of 4.4 (95% range 0.00–10). A 5-year backtest shows a typical error of ±47.9%, with 100% 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 →
20254.70.0011
20264.60.0010
20274.60.0010
20284.50.0010
20294.40.0010

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 →
Boulder11220241982
Meeteetse7220241991
Carter6820162006
Cody4820241983
Green River4419841977
Mtn View3620241980
Fontenelle3320241982
Riverside2920241968
Harmony2720232009
Crowheart2220211987
Carter 22120242017
Ethete1920241991
Sybille Cyn1820241980
Savery1719951989
Walcott1620241982
Wyarno1420241974
Dubois1420241968
Gebo1420241980
Warbonnet1420242008
Lovell1320241989
Arvada1320241997
Anchor1320181993
Ne Entrance1220211982
Cumberland1220241977
Dayton1220241980

Black-billed Magpie Population Trend in Other States

alaskaarizonacaliforniacoloradoidahokansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotautahwashington

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