BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Bald Eagle In Great Basin

All regionsGreat BasinGeneralists

Bald Eagle in Great Basin has surged: up 458% on the route-weighted index since 1975.

+458%Since 1975TrendPercent 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 →
82Routes 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 →
48YearsYears 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 Great Basin: up 458% on the route-weighted index since 1975.

Bald Eagle In Great Basin Population Forecast

If the recent trend holds, Bald Eagle in Great Basin is projected to fall about 22% by 2029 — from 0.36 in 2024 to a central estimate of 0.28 (95% range 0.18–0.39). A 5-year backtest shows a typical error of ±23.3%, with 80% of held-out values landing inside the 95% band.

-22%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 →
0.28Projected 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 →
0.18–0.3995% 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 →
±23.3%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 Great Basin is projected to fall about 22% by 2029 — from 0.36 in 2024 to a central estimate of 0.28 (95% range 0.18–0.39). A 5-year backtest shows a typical error of ±23.3%, with 80% 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 →
20250.260.160.36
20260.270.170.37
20270.270.170.37
20280.280.180.38
20290.280.180.39

Routes In Great Basin

Routes recording Bald Eagle in Great Basin.
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 →
CraneOREGON82024
JosephOREGON72024
Modoc Point 2OREGON72024
Davis CreekCALIFORNIA42023
BatesIDAHO42019
MerrillOREGON42022
NighthawkWASHINGTON42024
Iron GateCALIFORNIA32019
BakerIDAHO32022
LeadoreIDAHO32024
Modoc PointOREGON32018
TwispWASHINGTON32019
KendallWASHINGTON32024
YakimaWASHINGTON32024
IngallsCALIFORNIA21997
LikelyCALIFORNIA22024
DorrisCALIFORNIA22018
MacdoelCALIFORNIA22019
Crowder FlatCALIFORNIA22007
Iron SpringsIDAHO22024
PicaboIDAHO22009
Lost RiverIDAHO22008
ImnahaOREGON22024
Davis LakeOREGON22024
Wizard FallsOREGON22015

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