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

Prairie Falcon Population Trend in Colorado

All statesGeneralists

Prairie Falcon in Colorado has fallen sharply: down 67% on the route-weighted index since 1975.

-67%Since 1975TrendPercent 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 →
85Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Prairie 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 →

long arc declinecomputed 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 →

Prairie Falcon has fallen sharply in Colorado: down 67% on the route-weighted index since 1975.

Prairie Falcon Population Forecast in Colorado

If the recent trend holds, Prairie Falcon in Colorado is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±163.9%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.07Projected 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 →
0.00–0.1595% 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 →
±163.9%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, Prairie Falcon in Colorado is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±163.9%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.070.000.15
20260.070.000.15
20270.070.000.15
20280.070.000.15
20290.070.000.15

Prairie Falcon Survey Routes in Colorado

Routes recording Prairie 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 →
Fleming720031981
Wray Gulch320051988
Briggsdale220181986
Moffat220211980
Blanca219811981
Alamosa220152011
Piedra220122012
Ragged Mtn.220112011
Ellicott220171995
Maybell120222022
Yampa119971987
Harmony120101992
Pinneo119901990
Buford120121978
Aspen120182018
Kiowa120131991
Last Chance120091980
Abarr120101975
Delta119741974
Colona120022002
Rush120191999
Boyero120152014
Mica Butte119821973
Gilpin120171975
Two Buttes120111990

Prairie Falcon Population Trend in Other States

arizonacaliforniaidahokansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwyoming

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