BirdAnalyst
Species · Idaho · BBS 2026 Release · 1966–2025

Osprey Population Trend in Idaho

All statesBirds of prey

Osprey in Idaho has surged: up 110% on the route-weighted index since 1972.

+110%Since 1972TrendPercent 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 →
37Routes 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 →
52YearsYears 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 IdahoNotable 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 Idaho: up 110% on the route-weighted index since 1972.

Osprey Population Forecast in Idaho

If the recent trend holds, Osprey in Idaho is projected to stay roughly flat through 2030, near 0.42 (95% range 0.02–0.82). A 5-year backtest shows a typical error of ±42.7%, with 100% of held-out values landing inside the 95% band.

+5%Change by 2030TrendPercent 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 →
0.42Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.02–0.8295% 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 →
±42.7%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 Idaho is projected to stay roughly flat through 2030, near 0.42 (95% range 0.02–0.82). A 5-year backtest shows a typical error of ±42.7%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.410.010.81
20270.410.020.81
20280.420.020.81
20290.420.020.82
20300.420.020.82

Osprey Survey Routes in Idaho

Routes recording Osprey in Idaho.
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 →
Cascade1319841968
Ririe520251986
Bates520231988
Nezperce320121969
Centerville320251972
Cabarton320241985
Naples220211978
Gifford219971995
Lolo Pass220141995
Cape Horn220241989
Rochat Divde220251993
Springfield220181994
Coolin220211986
Pierce219921992
Featherville220251989
Daniels Res219981993
Preston220161988
Sawtooth Cty220091989
Mivoden120251982
Avery120001996
Grangeville119941994
Golden120161993
Baker120211990
Challis120242024
Leadore119811981

Osprey Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.