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Species · California · BBS 2025 Release · 1966–2024

Black-billed Magpie Population Trend in California

All statesGeneralists

Black-billed Magpie in California has surged: up 101% on the route-weighted index since 1971.

+101%Since 1971
31Routes In State
55Years

Notable Black-billed Magpie Trends in California

long arc increasecomputed index

Black-billed Magpie has surged in California: up 101% on the route-weighted index since 1971.

Black-billed Magpie Population Forecast in California

If the recent trend holds, Black-billed Magpie in California is projected to rise about 94% by 2029 — from 0.77 in 2024 to a central estimate of 1.5 (95% range 0.54–2.5). A 5-year backtest shows a typical error of ±290.2%, with 20% of held-out values landing inside the 95% band.

+94%Change by 2029
1.5Projected 2029 index
0.54–2.595% range
±290.2%Backtest error
19692029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20251.50.512.4
20261.50.522.4
20271.50.532.5
20281.50.542.5
20291.50.542.5

Black-billed Magpie Survey Routes in California

Routes recording Black-billed Magpie in California.
Macdoel3520191972
Cedarville2420241974
Davis Creek1920241972
Ingalls1720011973
Gazelle1320211988
Likely920241971
Iron Gate720191988
Honey Lake620241972
Clear Lk Res620181972
Yreka520191973
Paxton420241998
Dorris420191972
Crowley Lake320221977
Madeline320241997
Mt Shasta320191972
Nubieber220171970
Dardanelle220141973
Big Pine219811969
Sattley220241972
Bridgeport219761972
Genesee220241974
Bodie220241982
Tionesta120061997
Crowder Flat120192013
Haiwee Res119921992

Black-billed Magpie Population Trend in Other States

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