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

Black-billed Magpie Population Trend in Oregon

All statesGeneralists

Black-billed Magpie in Oregon has declined: down 44% on the route-weighted index since 1970.

-44%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 →
72Routes 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 OregonNotable 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 Oregon. See the full index history below.

Black-billed Magpie Population Forecast in Oregon

If the recent trend holds, Black-billed Magpie in Oregon is projected to fall about 40% by 2030 — from 4.2 in 2025 to a central estimate of 2.6 (95% range 0.00–5.6). A 5-year backtest shows a typical error of ±25%, with 100% of held-out values landing inside the 95% band.

-40%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 →
2.6Projected 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 →
0.00–5.695% 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 Oregon is projected to fall about 40% by 2030 — from 4.2 in 2025 to a central estimate of 2.6 (95% range 0.00–5.6). A 5-year backtest shows a typical error of ±25%, 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 →
20262.80.005.9
20272.80.005.8
20282.70.005.8
20292.60.005.7
20302.60.005.6

Black-billed Magpie Survey Routes in Oregon

Routes recording Black-billed Magpie in Oregon.
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 →
Ordnance5819791971
Summit Pr5120251980
Modoc Point3620181969
Sparta3320251971
Modoc Point 22720252024
Deschutes2520251968
Newbridge2420251992
Joseph2320251971
Merrill2320221993
Catlow Rim2320251993
Madras2020251997
Pendleton1920251972
Unity1920251992
Alvord Lake1720251968
Bridgeport1620251986
Umatilla1620221988
Trout Creek1420251997
Hash Rock1320251983
Malheur Nwr1220221986
Eagle Rock1119791971
Donelly 21020252018
Monument1020251993
Zumwalt920051995
Flook Lake820162003
Blizzard Gap720251984

Black-billed Magpie Population Trend in Other States

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