BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Bald Eagle In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGeneralists

Bald Eagle in Prairie Hardwood Transition has surged: up 44× on the route-weighted index since 1983.

44×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 →
99Routes 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 →
41YearsYears 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 Prairie Hardwood Transition: up 44× on the route-weighted index since 1983.

Bald Eagle In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Bald Eagle in Prairie Hardwood Transition is projected to fall about 18% by 2029 — from 0.56 in 2024 to a central estimate of 0.46 (95% range 0.34–0.58). A 5-year backtest shows a typical error of ±21.9%, with 40% of held-out values landing inside the 95% band.

-18%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 →
0.46Projected 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 →
0.34–0.5895% 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 →
±21.9%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 Prairie Hardwood Transition is projected to fall about 18% by 2029 — from 0.56 in 2024 to a central estimate of 0.46 (95% range 0.34–0.58). A 5-year backtest shows a typical error of ±21.9%, with 40% of held-out values landing inside the 95% band.19712029
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 →
20250.420.290.54
20260.430.300.55
20270.440.310.56
20280.450.330.57
20290.460.340.58

Routes In Prairie Hardwood Transition

Routes recording Bald Eagle in Prairie 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 →
Sherburne NrMINNESOTA62024
CochraneWISCONSIN42024
OmroWISCONSIN41996
MerrillWISCONSIN32024
MatherWISCONSIN32023
CascoWISCONSIN32024
Rolling GrndWISCONSIN32024
GuilfordILLINOIS22023
Cherry Val 2ILLINOIS22013
FestinaIOWA22024
Maple RapidsMICHIGAN22023
MillvilleMINNESOTA22018
MinnetonkaMINNESOTA22024
PrincetonMINNESOTA22024
St StephenMINNESOTA22006
EdwardsMINNESOTA22023
Le CenterMINNESOTA22023
AshbyMINNESOTA22014
KingswayOHIO22022
HudsonWISCONSIN22024
DresserWISCONSIN22024
LoraineWISCONSIN22018
TrempealeauWISCONSIN22024
Wis RapidsWISCONSIN22023
ManawaWISCONSIN22016

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