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Species · Oregon · BBS 2026 Release · 1966–2025

Black-headed Grosbeak Population Trend in Oregon

All statesForest birds

Black-headed Grosbeak in Oregon has edged up: up 13% on the route-weighted index since 1970.

+13%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 →
118Routes 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 Black-headed Grosbeak 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 →

No notable trend signals for Black-headed Grosbeak in Oregon. See the full index history below.

Black-headed Grosbeak Population Forecast in Oregon

If the recent trend holds, Black-headed Grosbeak in Oregon is projected to stay roughly flat through 2030, near 6.8 (95% range 5.0–8.6). A 5-year backtest shows a typical error of ±8.3%, with 100% of held-out values landing inside the 95% band.

-3%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 →
6.8Projected 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 →
5.0–8.695% 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 →
±8.3%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, Black-headed Grosbeak in Oregon is projected to stay roughly flat through 2030, near 6.8 (95% range 5.0–8.6). A 5-year backtest shows a typical error of ±8.3%, 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 →
20266.74.98.5
20276.75.08.5
20286.85.08.5
20296.85.08.6
20306.85.08.6

Black-headed Grosbeak Survey Routes in Oregon

Routes recording Black-headed Grosbeak 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 →
Secret Val4220251975
Harlan 24020252011
Scappoose3520251995
Days Creek3420251970
Ruch3320251992
Lorane3220251993
Prospect3120251993
Sams Valley3020251993
Garfield2920251973
Selma2920251993
Salado2620251968
Fisher2320101997
Sparta2219991973
Derby2119931968
Klickitat Mt2119961993
Badger Creek2020251992
Elkton1920251972
Emigrant Lk1820011972
Glasgow1820251986
Coquille1820251994
Sandy River1820061993
Umpqua1720251968
Hazel Camp1520221975
Hauser1419851970
Lobster Creek1420252025

Black-headed Grosbeak Population Trend in Other States

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