BirdAnalyst
Species · Oregon · BBS 2025 Release · 1966–2024

Black-headed Grosbeak Population Trend in Oregon

All statesGeneralists

Black-headed Grosbeak in Oregon has held roughly steady: up 5% on the route-weighted index since 1970.

+5%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 →
115Routes 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 →
56YearsYears 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 rise about 10% by 2029 — from 6.1 in 2024 to a central estimate of 6.8 (95% range 5.0–8.6). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.

+10%Change by 2029TrendPercent 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 2029 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 →
±9%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 rise about 10% by 2029 — from 6.1 in 2024 to a central estimate of 6.8 (95% range 5.0–8.6). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.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 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 →
20256.74.98.5
20266.74.98.5
20276.74.98.5
20286.74.98.5
20296.85.08.6

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 →
Lorane5420241993
Ruch5120231992
Secret Val3720221975
Days Creek3020241970
Sams Valley3020241993
Prospect2720241993
Selma2620241993
Harlan 22420242011
Garfield2320231973
Coquille2320241994
Fisher2320101997
Sparta2219991973
Elkton2220241972
Derby2119931968
Mt Hood2120241972
Klickitat Mt2119961993
Salado1920241968
Wedderburn1820241970
Emigrant Lk1820011972
Sandy River1820061993
Scio1720241971
Glasgow1720241986
Umpqua1520241968
Hazel Camp1520221975
Hauser1419851970

Black-headed Grosbeak Population Trend in Other States

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