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

Peregrine Falcon Population Trend in Colorado

All statesGeneralists

Peregrine Falcon in Colorado has surged: up 257% on the route-weighted index since 1999.

+257%Since 1999TrendPercent 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 →
35Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Peregrine Falcon 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 Peregrine Falcon in Colorado. See the full index history below.

Peregrine Falcon Population Forecast in Colorado

If the recent trend holds, Peregrine Falcon in Colorado is projected to fall about 19% by 2029 — from 0.05 in 2024 to a central estimate of 0.04 (95% range 0.01–0.07). A 5-year backtest shows a typical error of ±33.5%, with 80% of held-out values landing inside the 95% band.

-19%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 →
0.04Projected 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 →
0.01–0.0795% 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 →
±33.5%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, Peregrine Falcon in Colorado is projected to fall about 19% by 2029 — from 0.05 in 2024 to a central estimate of 0.04 (95% range 0.01–0.07). A 5-year backtest shows a typical error of ±33.5%, with 80% of held-out values landing inside the 95% band.19972029
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 →
20250.040.010.07
20260.040.010.07
20270.040.010.07
20280.040.010.07
20290.040.010.07

Peregrine Falcon Survey Routes in Colorado

Routes recording Peregrine Falcon 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 →
Piedra320072007
Wray Gulch220172007
Baxter Pass220241998
Maybell120152015
Yampa120092009
Mount Evans120242024
Mesaverde Np120231998
Douglas Pass120232023
Rosevale120222014
Cheesman Lk120062006
Colona120102010
Parlin120192019
Lamar120192019
Falfa120242024
Rio Grnds Rs120242007
Uncompahgre120002000
Dinosaur120182018
Doyleville120222022
Guffey120222017
Lay120212021
Steamboat L.120222022
Alamosa120112011
Powderhorn120222018
Gribbles Prk120212021
Karval120172017

Peregrine Falcon Population Trend in Other States

alabamaalaskaarizonacaliforniaconnecticutdelawareidahoindianamainemarylandmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorkoklahomaoregonpennsylvaniatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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