BirdAnalyst
Species · Oregon · BBS 2026 Release · 1966–2025

Brewer's Blackbird Population Trend in Oregon

All statesGeneralists

Brewer's Blackbird in Oregon has fallen sharply: down 57% on the route-weighted index since 1970.

-57%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
130Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Brewer's Blackbird Trends in OregonNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Brewer's Blackbird has fallen sharply in Oregon: down 57% on the route-weighted index since 1970.

Brewer's Blackbird Population Forecast in Oregon

If the recent trend holds, Brewer's Blackbird in Oregon is projected to fall about 48% by 2030 — from 19 in 2025 to a central estimate of 9.6 (95% range 0.00–23). A 5-year backtest shows a typical error of ±43.2%, with 100% of held-out values landing inside the 95% band.

-48%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
9.6Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2395% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±43.2%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Brewer's Blackbird in Oregon is projected to fall about 48% by 2030 — from 19 in 2025 to a central estimate of 9.6 (95% range 0.00–23). A 5-year backtest shows a typical error of ±43.2%, with 100% of held-out values landing inside the 95% band.19682030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
2026120.0025
2027120.0025
2028110.0024
2029100.0023
20309.60.0023

Brewer's Blackbird Survey Routes in Oregon

Routes recording Brewer's Blackbird in Oregon.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Joseph22920251971
Modoc Point 217020252024
Princeton14219851972
Modoc Point13420181969
Malheur Nwr12120221986
Bridgeport11320251986
Umatilla10920251988
Emigrant Lk10220011972
Sparta9420251971
Catlow Rim8120251993
Dayton6820251973
Pendleton6620251972
Bly5920011973
Crane5920241993
Zumwalt5920051995
Warner Vally5620241993
Fandango Can4920251977
Clover Creek4320251972
Umpqua4120251968
Bly 24120252007
Flook Lake4120251994
Salem4020251993
Malheur Res.3820232022
Sandy River3620061993
Lakeview3220251996

Brewer's Blackbird Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.