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

Peregrine Falcon Population Trend in Arizona

All statesGeneralists

Peregrine Falcon in Arizona has fallen sharply: down 64% on the route-weighted index since 1978.

-64%Since 1978TrendPercent 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 →
26Routes 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 →
25YearsYears 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 ArizonaNotable 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 Arizona: down 64% on the route-weighted index since 1978.

Peregrine Falcon Population Forecast in Arizona

If the recent trend holds, Peregrine Falcon in Arizona is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±30.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0895% 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 →
±30.2%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 Arizona is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±30.2%, with 100% of held-out values landing inside the 95% band.19692028
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 →
20240.030.000.09
20250.030.000.09
20260.020.000.08
20270.020.000.08
20280.020.000.08

Peregrine Falcon Survey Routes in Arizona

Routes recording Peregrine Falcon in Arizona.
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 →
Sunizona319921969
Blue219871987
Forest Lakes220032003
Mt Trumbull119921992
House Rock120192019
Portal120161977
Oatman120081994
Wikieup120182017
Laguna120232023
Dateland120212021
Pomerene119941994
Patagonia120172017
Cutter 2120162016
Toroweap120211999
Dry Park120082008
Page120122012
Many Farms119931993
Williams120182018
Skull Valley120112011
Redington120182009
Mt. Graham120142013
Mcneal120062006
Navajo Trail120161994
Sunizona 2120122012
Peach Spring120112008

Peregrine Falcon Population Trend in Other States

alabamaalaskacaliforniacoloradoconnecticutdelawareidahoindianamainemarylandmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorkoklahomaoregonpennsylvaniatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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