BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Bald Eagle In BCR 4

All regionsBCR 4Generalists

Bald Eagle in BCR 4 has increased: up 31% on the route-weighted index since 1983.

+31%Since 1983TrendPercent 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 →
46Routes 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 →
42YearsYears 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 →

No notable trend signals for Bald Eagle in BCR 4. See the full index history below.

Bald Eagle In BCR 4 Population Forecast

If the recent trend holds, Bald Eagle in BCR 4 is projected to stay roughly flat through 2029, near 0.53 (95% range 0.13–0.93). A 5-year backtest shows a typical error of ±17.9%, with 100% of held-out values landing inside the 95% band.

+1%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 →
0.53Projected 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 →
0.13–0.9395% 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 →
±17.9%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 BCR 4 is projected to stay roughly flat through 2029, near 0.53 (95% range 0.13–0.93). A 5-year backtest shows a typical error of ±17.9%, with 100% of held-out values landing inside the 95% band.19762029
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 →
20250.510.110.91
20260.520.120.92
20270.520.120.92
20280.530.130.93
20290.530.130.93

Routes In BCR 4

Routes recording Bald Eagle in BCR 4.
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 →
KuskulanaALASKA52022
SlanaALASKA42024
KachemakALASKA42024
KalifonskyALASKA32022
Bear CreekALASKA31986
Birch LakeALASKA22024
Swan Lake RdALASKA22003
Burma RoadALASKA22007
Hather CreekALASKA22021
McgrathALASKA21998
Anvik RiverALASKA22024
Kanuti LakeALASKA22024
CircleALASKA12019
Tower BluffsALASKA12008
ChistochinaALASKA12024
NorthwayALASKA12018
MaclarenALASKA12011
MonahanALASKA12021
CantwellALASKA12018
Goose BayALASKA11976
Skilak LakeALASKA11983
WillowALASKA11993
Kenny LakeALASKA12024
SourdoughALASKA12018
TonsinaALASKA12017

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