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

Osprey Population Trend in Michigan

All statesGeneralists

Osprey in Michigan has surged: up 811% on the route-weighted index since 1983.

+811%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 →
24Routes 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 →
38YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Osprey 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 →

Osprey has surged in Michigan: up 811% on the route-weighted index since 1983.

Osprey Population Forecast in Michigan

If the recent trend holds, Osprey in Michigan is projected to fall about 43% by 2029 — from 0.32 in 2024 to a central estimate of 0.18 (95% range 0.07–0.30). A 5-year backtest shows a typical error of ±40.2%, with 40% of held-out values landing inside the 95% band.

-43%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 →
0.18Projected 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 →
0.07–0.3095% 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 →
±40.2%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, Osprey in Michigan is projected to fall about 43% by 2029 — from 0.32 in 2024 to a central estimate of 0.18 (95% range 0.07–0.30). A 5-year backtest shows a typical error of ±40.2%, with 40% of held-out values landing inside the 95% band.19782029
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 →
20250.170.050.28
20260.170.060.29
20270.180.060.29
20280.180.070.29
20290.180.070.30

Osprey Survey Routes in Michigan

Routes recording Osprey 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 →
Remus520241992
Chippewa Lk.420241997
Gilchrist320001988
New Buffalo220032003
Brocky Lake220102008
Galesburg220242010
Bergland119901990
Hungerford120172017
Imp Lake119921992
Belding 2120242015
Ishpeming119851983
Seney Nwr120171992
Lawrence120182018
Muskallonge120181978
Tahquamenon119951993
Lake City120102010
Nashville120242019
Lapeer120242016
Riggsville119911991
Richmond120002000
Skeels119811981
Sand Lake119941994
Deckerville119961996
Cohoctah120242021

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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