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

Brown-headed Cowbird In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGeneralists

Brown-headed Cowbird in Sonoran and Mojave Deserts has declined: down 37% on the route-weighted index since 1970.

-37%Since 1970
76Routes In Region
56Years

Notable Signals

No notable trend signals for Brown-headed Cowbird in Sonoran and Mojave Deserts. See the full index history below.

Forecast

If the recent trend holds, Brown-headed Cowbird in Sonoran and Mojave Deserts is projected to rise about 67% by 2029 — from 2.4 in 2024 to a central estimate of 4.1 (95% range 0.00–8.3). A 5-year backtest shows a typical error of ±85.4%, with 100% of held-out values landing inside the 95% band.

+67%Change by 2029
4.1Projected 2029 index
0.00–8.395% range
±85.4%Backtest error
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 index95% low95% high
20254.10.008.3
20264.10.008.3
20274.10.008.3
20284.10.008.3
20294.10.008.3

Routes In Sonoran and Mojave Deserts

Routes recording Brown-headed Cowbird in Sonoran and Mojave Deserts.
TronaCALIFORNIA271977
Palo VerdeCALIFORNIA222024
AjoARIZONA162001
Cactus ForestARIZONA152024
Palo VerdeARIZONA122013
PisinimoARIZONA111993
Ash MeadowsNEVADA112023
CimaCALIFORNIA82021
LagunaARIZONA72023
ArabyARIZONA72023
Imperial DamCALIFORNIA72010
Jean LakeNEVADA71991
DatelandARIZONA62024
WickenburgARIZONA62023
FlorenceARIZONA51976
Red RockARIZONA52014
Palo Verde 2ARIZONA52024
Parker DamCALIFORNIA52007
Red Rock 2ARIZONA42024
Willow Beach 2ARIZONA42018
Hope 2ARIZONA42019
Coachella CnCALIFORNIA42000
BrawleyCALIFORNIA42009
WikieupARIZONA32024
QuartzsiteARIZONA32013

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