BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Black-billed Magpie In Sierra Nevada

All regionsSierra NevadaGeneralists

Black-billed Magpie in Sierra Nevada has declined: down 50% on the route-weighted index since 1974.

-50%Since 1974
7Routes In Region
51Years

Notable Signals

No notable trend signals for Black-billed Magpie in Sierra Nevada. See the full index history below.

Forecast

If the recent trend holds, Black-billed Magpie in Sierra Nevada is projected to rise about 114% by 2029 — from 0.42 in 2024 to a central estimate of 0.90 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±400%, with 80% of held-out values landing inside the 95% band.

+114%Change by 2029
0.90Projected 2029 index
0.00–1.995% range
±400%Backtest error
19722029
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
20250.890.001.9
20260.890.001.9
20270.900.001.9
20280.900.001.9
20290.900.001.9

Routes In Sierra Nevada

Routes recording Black-billed Magpie in Sierra Nevada.
PaxtonCALIFORNIA42024
DardanelleCALIFORNIA22014
SattleyCALIFORNIA22024
GeneseeCALIFORNIA22024
JohnsvilleCALIFORNIA11978
ChilcootCALIFORNIA12023
Last ChanceCALIFORNIA12019

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