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

Brewer's Blackbird In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Brewer's Blackbird in Sierra Madre Occidental has collapsed: down 76% on the route-weighted index since 1970.

-76%Since 1970
11Routes In Region
54Years

Notable Signals

long arc declinecomputed index

Brewer's Blackbird has collapsed in Sierra Madre Occidental: down 76% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Brewer's Blackbird in Sierra Madre Occidental is projected to fall about 83% by 2029 — from 1.2 in 2024 to a central estimate of 0.20 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±68.9%, with 100% of held-out values landing inside the 95% band.

-83%Change by 2029
0.20Projected 2029 index
0.00–2.295% range
±68.9%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
20250.410.002.5
20260.360.002.4
20270.310.002.4
20280.260.002.3
20290.200.002.2

Routes In Sierra Madre Occidental

Routes recording Brewer's Blackbird in Sierra Madre Occidental.
AlpineARIZONA302023
MaineARIZONA142024
BlueARIZONA91991
WilliamsARIZONA82019
Happy JackARIZONA82024
Mormon LakeARIZONA61975
PinetopARIZONA42021
San SimonARIZONA31979
SprucedaleARIZONA22022
Skull ValleyARIZONA12021
Clay SpringARIZONA12014

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