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

Purple Finch In Coastal California

All regionsCoastal CaliforniaGeneralists

Purple Finch in Coastal California has edged up: up 22% on the route-weighted index since 1970.

+22%Since 1970TrendPercent 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 →
69Routes 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 →
56YearsYears 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 Purple Finch in Coastal California. See the full index history below.

Purple Finch In Coastal California Population Forecast

If the recent trend holds, Purple Finch in Coastal California is projected to rise about 70% by 2029 — from 1.9 in 2024 to a central estimate of 3.2 (95% range 1.6–4.8). A 5-year backtest shows a typical error of ±111.1%, with 20% of held-out values landing inside the 95% band.

+70%Change 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 →
3.2Projected 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 →
1.6–4.895% 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 →
±111.1%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, Purple Finch in Coastal California is projected to rise about 70% by 2029 — from 1.9 in 2024 to a central estimate of 3.2 (95% range 1.6–4.8). A 5-year backtest shows a typical error of ±111.1%, with 20% of held-out values landing inside the 95% band.19682029
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 →
20253.11.54.7
20263.11.54.7
20273.21.64.8
20283.21.64.8
20293.21.64.8

Routes In Coastal California

Routes recording Purple Finch 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 →
San Benito Mtn.CALIFORNIA252009
Carmel ValCALIFORNIA232024
PescaderoCALIFORNIA222024
TehamaCALIFORNIA182022
Point ReyesCALIFORNIA172023
Waterman GapCALIFORNIA152024
FallsvaleCALIFORNIA131981
SisquocCALIFORNIA132014
Ora LomaCALIFORNIA121972
OnealsCALIFORNIA101973
Santa YnezCALIFORNIA92019
ValyermoCALIFORNIA92019
ColmaCALIFORNIA71972
StonyfordCALIFORNIA72018
LockwoodCALIFORNIA62024
Angelus OaksCALIFORNIA62017
Yokohl ValCALIFORNIA51996
Mt PinosCALIFORNIA52004
CoalingaCALIFORNIA52009
CohassetCALIFORNIA52024
FairfaxCALIFORNIA52024
Lake HemetCALIFORNIA51981
Mt BaldyCALIFORNIA52024
Lake CachumaCALIFORNIA52016
Mt Pinos 2CALIFORNIA52024

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