BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Bald Eagle In Coastal California

All regionsCoastal CaliforniaGeneralists

Bald Eagle in Coastal California has surged: up 567% on the route-weighted index since 2006.

+567%Since 2006TrendPercent 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 →
23Routes 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 →
19YearsYears 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 Coastal California: up 567% on the route-weighted index since 2006.

Bald Eagle In Coastal California Population Forecast

If the recent trend holds, Bald Eagle in Coastal California is projected to fall about 50% by 2029 — from 0.17 in 2024 to a central estimate of 0.09 (95% range 0.02–0.15). A 5-year backtest shows a typical error of ±62.4%, with 40% of held-out values landing inside the 95% band.

-50%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 →
0.09Projected 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 →
0.02–0.1595% 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 →
±62.4%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 Coastal California is projected to fall about 50% by 2029 — from 0.17 in 2024 to a central estimate of 0.09 (95% range 0.02–0.15). A 5-year backtest shows a typical error of ±62.4%, with 40% of held-out values landing inside the 95% band.19732029
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 →
20250.080.010.14
20260.080.020.14
20270.080.020.14
20280.080.020.15
20290.090.020.15

Routes In Coastal California

Routes recording Bald Eagle in Coastal California.
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 →
Lake BerryessaCALIFORNIA32024
Red BluffCALIFORNIA22018
S CatalinaCALIFORNIA22013
AdelaidaCALIFORNIA22024
CrestonCALIFORNIA22019
OrovilleCALIFORNIA22012
PolomaCALIFORNIA22017
RumseyCALIFORNIA12007
HughsonCALIFORNIA12023
MorenoCALIFORNIA11973
CoalingaCALIFORNIA12022
Point ReyesCALIFORNIA12018
Cuyamaca PkCALIFORNIA12023
GlennCALIFORNIA12015
WestleyCALIFORNIA12017
LockwoodCALIFORNIA12024
Yolla BollyCALIFORNIA12022
CoyoteCALIFORNIA12019
CopperopolisCALIFORNIA12010
OnealsCALIFORNIA12024
GreenfieldCALIFORNIA12024
Lake Hemet 2CALIFORNIA12018
Hollister 2CALIFORNIA12022

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