BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Black-billed Magpie In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestGeneralists

Black-billed Magpie in Northern Pacific Rainforest has fallen sharply: down 67% on the route-weighted index since 1974.

-67%Since 1974TrendPercent 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 →
16Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Black-billed Magpie has fallen sharply in Northern Pacific Rainforest: down 67% on the route-weighted index since 1974.

Black-billed Magpie In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Black-billed Magpie in Northern Pacific Rainforest is projected to rise about 366% by 2029 — from 0.05 in 2024 to a central estimate of 0.25 (95% range 0.00–0.52). A 5-year backtest shows a typical error of ±257.3%, with 80% of held-out values landing inside the 95% band.

+366%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 →
0.25Projected 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 →
0.00–0.5295% 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 →
±257.3%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 Northern Pacific Rainforest is projected to rise about 366% by 2029 — from 0.05 in 2024 to a central estimate of 0.25 (95% range 0.00–0.52). A 5-year backtest shows a typical error of ±257.3%, with 80% of held-out values landing inside the 95% band.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 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 →
20250.250.000.52
20260.250.000.52
20270.250.000.52
20280.250.000.52
20290.250.000.52

Routes In Northern Pacific Rainforest

Routes recording Black-billed Magpie in Northern Pacific Rainforest.
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 →
Yakutat (Short)ALASKA161984
GazelleCALIFORNIA132021
YrekaCALIFORNIA52019
Sheep MtnALASKA42017
Moose PassALASKA41992
HopeALASKA42023
SewardALASKA31992
Thompson PasALASKA32024
Mt ShastaCALIFORNIA32019
Kenai Lake (Short)ALASKA21992
Copper RiverALASKA22010
HainesALASKA11995
CordovaALASKA12024
YakutatALASKA12011
Alpenglow (Short)ALASKA11999
Emigrant Lake 2OREGON12010

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