BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Black-billed Magpie In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Black-billed Magpie in Boreal Hardwood Transition has surged: up 914% on the route-weighted index since 1981.

+914%Since 1981TrendPercent 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 →
15Routes 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 →
38YearsYears 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 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 Boreal Hardwood Transition: up 914% on the route-weighted index since 1981.

Black-billed Magpie In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Black-billed Magpie in Boreal Hardwood Transition is projected to rise about 106% by 2029 — from 0.24 in 2024 to a central estimate of 0.49 (95% range 0.25–0.74). A 5-year backtest shows a typical error of ±57.2%, with 80% of held-out values landing inside the 95% band.

+106%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 →
0.49Projected 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 →
0.25–0.7495% 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 →
±57.2%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 Boreal Hardwood Transition is projected to rise about 106% by 2029 — from 0.24 in 2024 to a central estimate of 0.49 (95% range 0.25–0.74). A 5-year backtest shows a typical error of ±57.2%, with 80% of held-out values landing inside the 95% band.19782029
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 →
20250.460.210.70
20260.470.220.71
20270.470.230.72
20280.480.240.73
20290.490.250.74

Routes In Boreal Hardwood Transition

Routes recording Black-billed Magpie in Boreal Hardwood Transition.
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 →
BagleyMINNESOTA132006
DebsMINNESOTA62024
NebishMINNESOTA52023
LudeMINNESOTA42023
Nett LakeMINNESOTA42024
Little ForkMINNESOTA32024
Pine RiverMINNESOTA22024
WaskishMINNESOTA22021
BlackduckMINNESOTA22021
BackusMINNESOTA12024
FloodwoodMINNESOTA12023
CohassetMINNESOTA12022
McgregorMINNESOTA12023
WarroadMINNESOTA12024
GreenbushMINNESOTA12024

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