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

Grasshopper Sparrow In Coastal California

All regionsCoastal CaliforniaGrassland birds

Grasshopper Sparrow in Coastal California has surged: up 615% on the route-weighted index since 1974.

+615%Since 1974
37Routes In Region
51Years

Notable Signals

long arc increasecomputed index

Grasshopper Sparrow has surged in Coastal California: up 615% on the route-weighted index since 1974.

Forecast

If the recent trend holds, Grasshopper Sparrow in Coastal California is projected to rise about 437% by 2029 — from 0.06 in 2024 to a central estimate of 0.34 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±508.6%, with 100% of held-out values landing inside the 95% band.

+437%Change by 2029
0.34Projected 2029 index
0.00–0.8695% range
±508.6%Backtest error
19722029
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
20250.340.000.85
20260.340.000.86
20270.340.000.86
20280.340.000.86
20290.340.000.86

Routes In Coastal California

Routes recording Grasshopper Sparrow in Coastal California.
JofeganCALIFORNIA102023
AnzaCALIFORNIA61995
Cp. PendletonCALIFORNIA52004
Red BluffCALIFORNIA32022
RiovistaCALIFORNIA32014
Tres PinosCALIFORNIA32002
Carmel ValCALIFORNIA32022
VentucopaCALIFORNIA31999
Carrizo PlnCALIFORNIA32003
HollisterCALIFORNIA21991
Morro BayCALIFORNIA22013
Elsinore MtnCALIFORNIA22022
Santa Cruz ICALIFORNIA21988
CrestonCALIFORNIA22008
JacksonCALIFORNIA21979
Tres Pinos 2CALIFORNIA22011
Jofegan 2CALIFORNIA22024
HughsonCALIFORNIA11996
Yokohl ValCALIFORNIA11996
Santa YnezCALIFORNIA11994
Orange CoveCALIFORNIA12006
Point ReyesCALIFORNIA12023
FairfaxCALIFORNIA12007
FolsomCALIFORNIA11984
El ToroCALIFORNIA11986

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