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

Cassin's Finch In Coastal California

All regionsCoastal CaliforniaGeneralists

Cassin's Finch in Coastal California has collapsed: down 87% on the route-weighted index since 1971.

-87%Since 1971TrendPercent 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 →
50YearsYears 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 →

Cassin's Finch has collapsed in Coastal California: down 87% on the route-weighted index since 1971.

Cassin's Finch In Coastal California Population Forecast

If the recent trend holds, Cassin's Finch in Coastal California is projected to fall about 100% by 2026 — from 0.19 in 2021 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±229.4%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2026TrendPercent 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 →
0.00Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–3.295% 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 →
±229.4%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, Cassin's Finch in Coastal California is projected to fall about 100% by 2026 — from 0.19 in 2021 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±229.4%, with 100% of held-out values landing inside the 95% band.19692026
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 →
20220.000.003.2
20230.000.003.2
20240.000.003.2
20250.000.003.2
20260.000.003.2

Routes In Coastal California

Routes recording Cassin's 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 →
Lockwood ValCALIFORNIA282006
FallsvaleCALIFORNIA191975
ValyermoCALIFORNIA132019
Green ValleyCALIFORNIA112019
Cleveland NfCALIFORNIA112000
Big BearCALIFORNIA91986
Mt Pinos 2CALIFORNIA82021
Mt PinosCALIFORNIA62004
TujungaCALIFORNIA31987
Lake HemetCALIFORNIA31986
Angelus OaksCALIFORNIA32013
Cal Hot SpgsCALIFORNIA32010
Lake CachumaCALIFORNIA21983
Lake SuccessCALIFORNIA11973
Mt BaldyCALIFORNIA12014
TehamaCALIFORNIA11981
AlamarCALIFORNIA12009
Hough SpringsCALIFORNIA12002

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