BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

Brewer's Sparrow In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGeneralists

Brewer's Sparrow in Sonoran and Mojave Deserts has collapsed: down 80% on the route-weighted index since 1972.

-80%Since 1972
25Routes In Region
50Years

Notable Signals

long arc declinecomputed index

Brewer's Sparrow has collapsed in Sonoran and Mojave Deserts: down 80% on the route-weighted index since 1972.

Forecast

If the recent trend holds, Brewer's Sparrow in Sonoran and Mojave Deserts is projected to fall about 100% by 2029 — from 0.17 in 2024 to a central estimate of 0.00 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±85%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–1.395% range
±85%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
20250.010.001.3
20260.000.001.3
20270.000.001.3
20280.000.001.3
20290.000.001.3

Routes In Sonoran and Mojave Deserts

Routes recording Brewer's Sparrow in Sonoran and Mojave Deserts.
Willow SpgsCALIFORNIA111977
Eureka ValCALIFORNIA72016
Silver PeakNEVADA71973
TecopaCALIFORNIA61987
Joshua TreeCALIFORNIA61991
OnyxCALIFORNIA51998
Calif CityCALIFORNIA41978
Alamo Res.ARIZONA31992
WildroseCALIFORNIA32021
Greenwater VCALIFORNIA32024
Haiwee ResCALIFORNIA22001
Valley WellsCALIFORNIA22003
Val Of FireNEVADA22017
AntaresARIZONA12024
UbehebeCALIFORNIA12021
DarwinCALIFORNIA12005
IvanpahCALIFORNIA12003
CimaCALIFORNIA11993
Lone PineCALIFORNIA12009
Death ValleyCALIFORNIA12023
Kelso ValleyCALIFORNIA12024
Cholla Gard.CALIFORNIA12015
Jean LakeNEVADA12010
Silver Peak 2NEVADA12018
Ash MeadowsNEVADA11998

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