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

Bald Eagle In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Bald Eagle in Boreal Hardwood Transition has surged: up 765% on the route-weighted index since 1977.

+765%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 →
88Routes 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 →
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 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 →

Bald Eagle has surged in Boreal Hardwood Transition: up 765% on the route-weighted index since 1977.

Bald Eagle In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Bald Eagle in Boreal Hardwood Transition is projected to fall about 12% by 2029 — from 0.36 in 2024 to a central estimate of 0.32 (95% range 0.24–0.39). A 5-year backtest shows a typical error of ±25.5%, with 80% of held-out values landing inside the 95% band.

-12%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 →
0.32Projected 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 →
0.24–0.3995% 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 →
±25.5%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, Bald Eagle in Boreal Hardwood Transition is projected to fall about 12% by 2029 — from 0.36 in 2024 to a central estimate of 0.32 (95% range 0.24–0.39). A 5-year backtest shows a typical error of ±25.5%, with 80% of held-out values landing inside the 95% band.19742029
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 →
20250.290.220.37
20260.300.220.38
20270.310.230.38
20280.310.230.39
20290.320.240.39

Routes In Boreal Hardwood Transition

Routes recording Bald Eagle 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 →
Wigwam BayMINNESOTA32023
BabbittMINNESOTA32016
Tamarac NwrMINNESOTA32023
RhinelanderWISCONSIN32021
Lake CityMICHIGAN22010
SkeelsMICHIGAN22007
OberlinMICHIGAN22024
CathroMICHIGAN22012
Seney NwrMICHIGAN22010
CromwellMINNESOTA22024
Pine RiverMINNESOTA22024
FloodwoodMINNESOTA22019
LudeMINNESOTA22022
BrainerdMINNESOTA22024
BlackduckMINNESOTA22022
GlendaleMINNESOTA22022
WarroadMINNESOTA22024
GreenbushMINNESOTA22021
NebishMINNESOTA22023
Nett LakeMINNESOTA22021
GilmanWISCONSIN22024
WausaukeeWISCONSIN22013
Washington IWISCONSIN22024
OntonagonMICHIGAN12019
BerglandMICHIGAN12019

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