BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Bronzed Cowbird In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Bronzed Cowbird in Sierra Madre Occidental has fallen sharply: down 72% on the route-weighted index since 1970.

-72%Since 1970
17Routes In Region
56Years

Notable Signals

long arc declinecomputed index

Bronzed Cowbird has fallen sharply in Sierra Madre Occidental: down 72% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Bronzed Cowbird in Sierra Madre Occidental is projected to fall about 100% by 2029 — from 0.11 in 2024 to a central estimate of 0.00 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±231.1%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–1.895% range
±231.1%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
20250.000.001.8
20260.000.001.8
20270.000.001.8
20280.000.001.8
20290.000.001.8

Routes In Sierra Madre Occidental

Routes recording Bronzed Cowbird in Sierra Madre Occidental.
Bartlett ResARIZONA42021
San SimonARIZONA31980
SunizonaARIZONA31986
PortalARIZONA32023
PomereneARIZONA22023
PatagoniaARIZONA22024
RuckerARIZONA21997
PrescottARIZONA11999
Peña BlancaARIZONA12001
Skull ValleyARIZONA12021
RedingtonARIZONA12006
AmadoARIZONA12023
SahuaritaARIZONA12007
McnealARIZONA12001
Carr MtnARIZONA12014
Sunizona 2ARIZONA12022
DragoonARIZONA12002

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