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Species · Alaska · BBS 2026 Release · 1966–2025

Black-billed Magpie Population Trend in Alaska

All statesGeneralists

Black-billed Magpie in Alaska has surged: up 106% on the route-weighted index since 1977.

+106%Since 1977TrendPercent 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 →
58Routes 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 →
47YearsYears 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 AlaskaNotable 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 increasecomputed 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 surged in Alaska: up 106% on the route-weighted index since 1977.

Black-billed Magpie Population Forecast in Alaska

If the recent trend holds, Black-billed Magpie in Alaska is projected to stay roughly flat through 2030, near 1.2 (95% range 0.04–2.3). A 5-year backtest shows a typical error of ±16.6%, with 100% of held-out values landing inside the 95% band.

-9%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 →
1.2Projected 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 →
0.04–2.395% 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 →
±16.6%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 Alaska is projected to stay roughly flat through 2030, near 1.2 (95% range 0.04–2.3). A 5-year backtest shows a typical error of ±16.6%, with 100% of held-out values landing inside the 95% band.19752030
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 →
20261.20.082.4
20271.20.072.3
20281.20.062.3
20291.20.052.3
20301.20.042.3

Black-billed Magpie Survey Routes in Alaska

Routes recording Black-billed Magpie in Alaska.
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 →
Kachemak1920251986
Yakutat (Short)1619841984
Kodiak1419841983
Cohoe1420232012
Kalifonsky1220252012
Anchor River1220251983
Homer919821977
Kodiak 2920251985
Chiniak520251985
Toklat520211983
Thompson Pas520252000
Sourdough520221998
Dillingham520171994
Hope420231993
Moose Pass419921983
Slana320241995
Mccarthy Rd2319991999
Seward319921984
Goose Bay319821976
Cottonwood319901987
Sheep Mtn320251983
Savage320251986
Kenai Lake (Short)219921992
Maclaren219861986
Willow220251994

Black-billed Magpie Population Trend in Other States

arizonacaliforniacoloradoidahokansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotautahwashingtonwyoming

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