BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Peregrine Falcon In Coastal California

All regionsCoastal CaliforniaGeneralists

Peregrine Falcon in Coastal California has surged: up 136% on the route-weighted index since 1979.

+136%Since 1979TrendPercent 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 →
18Routes 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 →

No notable trend signals for Peregrine Falcon in Coastal California. See the full index history below.

Peregrine Falcon In Coastal California Population Forecast

If the recent trend holds, Peregrine Falcon in Coastal California is projected to stay roughly flat through 2029, near 0.05 (95% range 0.02–0.09). A 5-year backtest shows a typical error of ±42.9%, 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 →
0.05Projected 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 →
0.02–0.0995% 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 →
±42.9%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, Peregrine Falcon in Coastal California is projected to stay roughly flat through 2029, near 0.05 (95% range 0.02–0.09). A 5-year backtest shows a typical error of ±42.9%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.050.010.08
20260.050.010.09
20270.050.010.09
20280.050.010.09
20290.050.020.09

Routes In Coastal California

Routes recording Peregrine Falcon in Coastal California.
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 →
HughsonCALIFORNIA12024
Morro BayCALIFORNIA12012
Point ReyesCALIFORNIA12021
OrlandCALIFORNIA11993
FolsomCALIFORNIA12008
S CatalinaCALIFORNIA12019
ValyermoCALIFORNIA12012
Cuyamaca PkCALIFORNIA11980
AdelaidaCALIFORNIA11978
GlennCALIFORNIA12015
AtwaterCALIFORNIA12012
Gold HillCALIFORNIA12011
Yolla BollyCALIFORNIA12018
Mark WestCALIFORNIA12021
OnealsCALIFORNIA12017
Buena VistaCALIFORNIA12017
PescaderoCALIFORNIA12012
Harbor Lake 2CALIFORNIA12024

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