BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Peregrine Falcon In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Peregrine Falcon in Sierra Madre Occidental has fallen sharply: down 73% on the route-weighted index since 1978.

-73%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 →
14Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
21YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Sierra Madre Occidental: down 73% on the route-weighted index since 1978.

Forecast

If the recent trend holds, Peregrine Falcon in Sierra Madre Occidental is projected to fall about 84% by 2023 — from 0.08 in 2018 to a central estimate of 0.01 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±64.5%, with 100% of held-out values landing inside the 95% band.

-84%Change by 2023TrendPercent 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 →
0.01Projected 2023 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1495% 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 →
±64.5%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 Sierra Madre Occidental is projected to fall about 84% by 2023 — from 0.08 in 2018 to a central estimate of 0.01 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±64.5%, with 100% of held-out values landing inside the 95% band.19692023
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 →
20190.030.000.15
20200.030.000.15
20210.020.000.14
20220.020.000.14
20230.010.000.14

Routes In Sierra Madre Occidental

Routes recording Peregrine Falcon in Sierra Madre Occidental.
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 →
SunizonaARIZONA31992
BlueARIZONA21987
Forest LakesARIZONA22003
Emory PassNEW-MEXICO22009
PomereneARIZONA11994
PatagoniaARIZONA12017
WilliamsARIZONA12018
Skull ValleyARIZONA12011
RedingtonARIZONA12018
Mt. GrahamARIZONA12014
McnealARIZONA12006
Carr MtnARIZONA12015
PortalARIZONA12016
Sunizona 2ARIZONA12012

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