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

Osprey Population Trend in Idaho

All statesGeneralists

Osprey in Idaho has risen sharply: up 52% on the route-weighted index since 1972.

+52%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 →
51YearsYears 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 risen sharply in Idaho: up 51% on the route-weighted index since 1972.

Osprey Population Forecast in Idaho

If the recent trend holds, Osprey in Idaho is projected to rise about 156% by 2029 — from 0.16 in 2024 to a central estimate of 0.41 (95% range 0.00–0.82). A 5-year backtest shows a typical error of ±79.5%, with 100% of held-out values landing inside the 95% band.

+156%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 →
0.41Projected 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 →
0.00–0.8295% 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 →
±79.5%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 rise about 156% by 2029 — from 0.16 in 2024 to a central estimate of 0.41 (95% range 0.00–0.82). A 5-year backtest shows a typical error of ±79.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.410.000.81
20260.410.000.81
20270.410.000.81
20280.410.000.82
20290.410.000.82

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
Ririe620231986
Bates520231988
Centerville420191972
Nezperce320121969
Sunbeam320171995
Cabarton320231985
Naples220211978
Mivoden220181982
Gifford219971995
Lolo Pass220141995
Cape Horn220241989
Springfield220181994
Coolin220211986
Pierce219921992
Daniels Res219981993
Preston220161988
Sawtooth Cty220091989
Avery120001996
Grangeville119941994
Golden120161993
Baker120211990
Challis120242024
Leadore119811981
N Fork Cda R120171993

Osprey Population Trend in Other States

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

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