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

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 →
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 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 19% by 2029 — from 3.1 in 2024 to a central estimate of 2.5 (95% range 0.00–5.6). A 5-year backtest shows a typical error of ±24.2%, with 100% of held-out values landing inside the 95% band.

-19%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 →
2.5Projected 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 →
0.00–5.695% 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 →
±24.2%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 19% by 2029 — from 3.1 in 2024 to a central estimate of 2.5 (95% range 0.00–5.6). A 5-year backtest shows a typical error of ±24.2%, 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 →
20252.80.005.9
20262.70.005.8
20272.70.005.7
20282.60.005.7
20292.50.005.6

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
Bridgeport4820221986
Modoc Point3620181969
Trout Creek3420211997
Sparta3320011971
Adrian3120211984
Newbridge3020241992
Clover Creek2820241972
Modoc Point 22620242024
Summit Pr2420241980
Deschutes2420241968
Merrill2320221993
Joseph2020241971
Hash Rock1820241983
Catlow Rim1720241993
Umatilla1620221988
Mikkalo1520231996
Wickiup1220241969
Malheur Nwr1220221986
Sheaville1220242012
Eagle Rock1119791971
Zumwalt920051995
Donelly 2920242018
Pendleton820241972
Flook Lake820162003

Black-billed Magpie Population Trend in Other States

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