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

Black-throated Sparrow In Coastal California

All regionsCoastal CaliforniaArid-land birds

Black-throated Sparrow in Coastal California has collapsed: down 83% on the route-weighted index since 1972.

-83%Since 1972
17Routes In Region
51Years

Notable Signals

long arc declinecomputed index

Black-throated Sparrow has collapsed in Coastal California: down 82% on the route-weighted index since 1972.

Forecast

If the recent trend holds, Black-throated Sparrow in Coastal California is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.42). A 5-year backtest shows a typical error of ±57.8%, with 100% of held-out values landing inside the 95% band.

+2%Change by 2029
0.07Projected 2029 index
0.00–0.4295% range
±57.8%Backtest error
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 index95% low95% high
20250.080.000.43
20260.080.000.43
20270.070.000.43
20280.070.000.42
20290.070.000.42

Routes In Coastal California

Routes recording Black-throated Sparrow in Coastal California.
Mt PinosCALIFORNIA71997
Green ValleyCALIFORNIA42023
Big BearCALIFORNIA31986
Cuyamaca PkCALIFORNIA31976
VentucopaCALIFORNIA31995
FolsomCALIFORNIA22012
FallsvaleCALIFORNIA21975
Mt LagunaCALIFORNIA21975
AnzaCALIFORNIA22003
JacumbaCALIFORNIA22024
Oak GroveCALIFORNIA12022
TujungaCALIFORNIA11970
Mesa GrandeCALIFORNIA12019
Carrizo PlnCALIFORNIA11977
CopperopolisCALIFORNIA12015
Lake Hemet 2CALIFORNIA11993
WoodlandsCALIFORNIA12024

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