BirdAnalyst
Species · BCR 35 · BBS 2025 Release · 1966–2024

Brown-headed Cowbird In Chihuahuan Desert

All regionsChihuahuan DesertGeneralists

Brown-headed Cowbird in Chihuahuan Desert has fallen sharply: down 66% on the route-weighted index since 1969.

-66%Since 1969
56Routes In Region
57Years

Notable Signals

long arc declinecomputed index

Brown-headed Cowbird has fallen sharply in Chihuahuan Desert: down 66% on the route-weighted index since 1969.

Forecast

If the recent trend holds, Brown-headed Cowbird in Chihuahuan Desert is projected to rise about 56% by 2029 — from 3.6 in 2024 to a central estimate of 5.5 (95% range 0.00–14). A 5-year backtest shows a typical error of ±89.3%, with 100% of held-out values landing inside the 95% band.

+56%Change by 2029
5.5Projected 2029 index
0.00–1495% range
±89.3%Backtest error
19672029
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
20255.80.0014
20265.70.0014
20275.70.0014
20285.60.0014
20295.50.0014

Routes In Chihuahuan Desert

Routes recording Brown-headed Cowbird in Chihuahuan Desert.
Quitman Cyn.TEXAS292009
MesillaNEW-MEXICO202000
San AntonioNEW-MEXICO171977
ColumbusNEW-MEXICO162024
ShafterTEXAS161985
Red RockNEW-MEXICO152024
MarathonTEXAS122022
Sunshine WllNEW-MEXICO102021
PumpvilleTEXAS102024
LongfellowTEXAS92024
OzonaTEXAS82022
Hatchet PeakNEW-MEXICO72024
ComstockTEXAS62023
Delaware CrkTEXAS62015
Sierra BlancTEXAS62023
Ft. DavisTEXAS62023
GageNEW-MEXICO52024
LaborcitaNEW-MEXICO52019
LangtryTEXAS52000
Devils R CynTEXAS52024
Salt FlatTEXAS52015
Chisos BasinTEXAS52019
PinonNEW-MEXICO42024
Lake ValleyNEW-MEXICO42024
Casa PiedraTEXAS42023

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