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

Peregrine Falcon Population Trend in Utah

All statesGeneralists

Peregrine Falcon in Utah has fallen sharply: down 51% on the route-weighted index since 1991.

-51%Since 1991TrendPercent 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 →
31Routes 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 →
33YearsYears 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 UtahNotable 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 →

Peregrine Falcon has fallen sharply in Utah: down 51% on the route-weighted index since 1991.

Peregrine Falcon Population Forecast in Utah

If the recent trend holds, Peregrine Falcon in Utah is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±59.4%, with 80% 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 →
0.02Projected 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 →
0.00–0.1095% 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 →
±59.4%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 Utah is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±59.4%, with 80% of held-out values landing inside the 95% band.19722029
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 →
20250.030.000.10
20260.030.000.10
20270.030.000.10
20280.030.000.10
20290.020.000.10

Peregrine Falcon Survey Routes in Utah

Routes recording Peregrine Falcon in Utah.
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 →
Main Canyon320012001
Hite220152005
Fayette220182018
Indian Peak220182006
Promontory120232011
Neponset Res120102001
Altonah119721972
Oak City120001996
Goshen120241998
Bryce Canyon119931993
Desert View120212021
Canyonlands120062005
Navajo Lake120221996
Boulder120211989
Aneth120142014
Bear River120222005
Randolph120222005
M Warner Res119951995
Callao120192019
Castle Dale120061996
Dixie Nf120021997
Glen Canyon120232010
Vernal120172017
Green River119991999
Newcastle120042004

Peregrine Falcon Population Trend in Other States

alabamaalaskaarizonacaliforniacoloradoconnecticutdelawareidahoindianamainemarylandmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorkoklahomaoregonpennsylvaniatennesseetexasvermontvirginiawashingtonwisconsinwyoming

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