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Species · Montana · BBS 2025 Release · 1966–2024

Brewer's Blackbird Population Trend in Montana

All statesGeneralists

Brewer's Blackbird in Montana has fallen sharply: down 55% on the route-weighted index since 1970.

-55%Since 1970
108Routes In State
56Years

Notable Brewer's Blackbird Trends in Montana

long arc declinecomputed index

Brewer's Blackbird has fallen sharply in Montana: down 55% on the route-weighted index since 1970.

Brewer's Blackbird Population Forecast in Montana

If the recent trend holds, Brewer's Blackbird in Montana is projected to fall about 39% by 2029 — from 18 in 2024 to a central estimate of 11 (95% range 1.8–20). A 5-year backtest shows a typical error of ±23.9%, with 100% of held-out values landing inside the 95% band.

-39%Change by 2029
11Projected 2029 index
1.8–2095% range
±23.9%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
2025122.921
2026122.621
2027122.321
2028112.120
2029111.820

Brewer's Blackbird Survey Routes in Montana

Routes recording Brewer's Blackbird in Montana.
Twin Bridges10219761968
St Mary10020081968
Lambert10020242021
Savage7020211969
Whitlash6720242009
St. Mary 26320242009
Glasgow5820241968
Hay Lake5720221988
Fort Logan5720242018
Raynesford5420242016
Reed Point5220241977
Cabin Creek5220242019
Albion5120241982
Clyde Park5020242018
Polson4920241972
Augusta4520241976
Freeman Creek4220162015
Boulder4120241969
Wolf Creek4120222015
Lindsay3720242015
Harlem3620211968
Saco3320242015
Glentana3120242015
Philipsburg3120242015
Lima3020241994

Brewer's Blackbird Population Trend in Other States

arizonacaliforniacoloradoidahoindianamichiganminnesotanebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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