BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Brewer's Blackbird In Northern Rockies

All regionsNorthern RockiesGeneralists

Brewer's Blackbird in Northern Rockies has fallen sharply: down 62% on the route-weighted index since 1970.

-62%Since 1970
204Routes In Region
56Years

Notable Signals

long arc declinecomputed index

Brewer's Blackbird has fallen sharply in Northern Rockies: down 62% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Brewer's Blackbird in Northern Rockies is projected to fall about 43% by 2029 — from 11 in 2024 to a central estimate of 6.4 (95% range 0.00–14). A 5-year backtest shows a typical error of ±19.2%, with 100% of held-out values landing inside the 95% band.

-43%Change by 2029
6.4Projected 2029 index
0.00–1495% range
±19.2%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
20258.20.7316
20267.70.2915
20277.30.0015
20286.90.0014
20296.40.0014

Routes In Northern Rockies

Routes recording Brewer's Blackbird in Northern Rockies.
Twin BridgesMONTANA1021976
St MaryMONTANA1002008
BoulderWYOMING982024
SpartaOREGON732001
St. Mary 2MONTANA632024
Fort LoganMONTANA572024
RandolphUTAH572024
RaynesfordMONTANA542024
MeeteetseWYOMING512024
DanielWYOMING511988
WalcottWYOMING512024
Clyde ParkMONTANA502024
PolsonMONTANA492024
Crane CreekIDAHO482019
HarmonyWYOMING462023
CascadeIDAHO451984
AugustaMONTANA452024
Freeman CreekMONTANA422016
BoulderMONTANA412024
Wolf CreekMONTANA412022
AlturasIDAHO381987
Malheur Res.OREGON382023
Green RiverWYOMING381984
ArmintoWYOMING342024
Patrick DrawWYOMING331980

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