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

Osprey Population Trend in Colorado

All statesBirds of prey

Osprey in Colorado has surged: up 393% on the route-weighted index since 1998.

+393%Since 1998TrendPercent 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 →
25Routes 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 →
29YearsYears 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 ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Osprey in Colorado. See the full index history below.

Osprey Population Forecast in Colorado

If the recent trend holds, Osprey in Colorado is projected to fall about 37% by 2030 — from 0.12 in 2025 to a central estimate of 0.08 (95% range 0.04–0.11). A 5-year backtest shows a typical error of ±23%, with 80% of held-out values landing inside the 95% band.

-37%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 →
0.08Projected 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 →
0.04–0.1195% 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 →
±23%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 Colorado is projected to fall about 37% by 2030 — from 0.12 in 2025 to a central estimate of 0.08 (95% range 0.04–0.11). A 5-year backtest shows a typical error of ±23%, with 80% of held-out values landing inside the 95% band.19882030
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 →
20260.070.030.10
20270.070.040.10
20280.070.040.11
20290.070.040.11
20300.080.040.11

Osprey Survey Routes in Colorado

Routes recording Osprey in Colorado.
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 →
Maybell220252025
Wray Gulch220252025
Steamboat L.220252014
De Beque220252003
Lake City 2220252016
Harmony120232023
Arsenal120072007
Aspen120252017
Last Chance120092009
Rio Grnds Rs120161994
Lost Lake120192000
Cortez 2120142014
Tarryall120192019
Ragged Mtn.120252025
Gold Hill 2120242019
Thomasville120172013
Haswell120112011
Neegrande120031998
Groundhog Rs120212021
Piedra120152001
Angora120222008
Gold Hill120061999
Rifle Falls120252017
Rollins Pass120212007
Cortez119881988

Osprey Population Trend in Other States

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

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