BirdAnalyst
Species · Michigan · BBS 2025 Release · 1966–2024

Bald Eagle Population Trend in Michigan

All statesGeneralists

Bald Eagle in Michigan has surged: up 406% on the route-weighted index since 1984.

+406%Since 1984TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
36YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bald Eagle Trends in MichiganNotable 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 Michigan: up 406% on the route-weighted index since 1984.

Bald Eagle Population Forecast in Michigan

If the recent trend holds, Bald Eagle in Michigan is projected to fall about 31% by 2029 — from 0.21 in 2024 to a central estimate of 0.15 (95% range 0.07–0.22). A 5-year backtest shows a typical error of ±39.9%, with 40% of held-out values landing inside the 95% band.

-31%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 →
0.15Projected 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 →
0.07–0.2295% 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 →
±39.9%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 Michigan is projected to fall about 31% by 2029 — from 0.21 in 2024 to a central estimate of 0.15 (95% range 0.07–0.22). A 5-year backtest shows a typical error of ±39.9%, with 40% 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 →
20250.130.060.21
20260.140.060.21
20270.140.060.22
20280.140.070.22
20290.150.070.22

Bald Eagle Survey Routes in Michigan

Routes recording Bald Eagle in Michigan.
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 →
Seney Nwr220101992
Lake City220102008
Skeels220072007
Oberlin220241992
Maple Rapids220232014
Cathro220122007
Ontonagon120192012
Bergland120191986
Hungerford120232007
Bootjack120171993
Ned Lake120171987
Chippewa Lk.120092001
Crystal Fls120241989
Gibbs City120222022
Maple Grove120242014
Ishpeming120161981
Imp Lake120192019
Wilson120042004
Creighton119861986
Walloon Lake 2120082008
Bear Lake120112011
Scottville120192012
Frederic 2120142008
Cluster Lakes120102010
Barry S.G.A. 2120172017

Bald Eagle Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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