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Species · Oregon · BBS 2025 Release · 1966–2024

Orange-crowned Warbler Population Trend in Oregon

All statesForest birds

Orange-crowned Warbler in Oregon has fallen sharply: down 65% on the route-weighted index since 1970.

-65%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 →
94Routes 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 Orange-crowned Warbler 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 →

Orange-crowned Warbler has fallen sharply in Oregon: down 65% on the route-weighted index since 1970.

Orange-crowned Warbler Population Forecast in Oregon

If the recent trend holds, Orange-crowned Warbler in Oregon is projected to fall about 27% by 2029 — from 1.4 in 2024 to a central estimate of 1.0 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±27.7%, with 100% of held-out values landing inside the 95% band.

-27%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 →
1.0Projected 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 →
0.00–2.295% 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 →
±27.7%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, Orange-crowned Warbler in Oregon is projected to fall about 27% by 2029 — from 1.4 in 2024 to a central estimate of 1.0 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±27.7%, 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 →
20251.20.062.4
20261.20.012.3
20271.10.002.3
20281.10.002.2
20291.00.002.2

Orange-crowned Warbler Survey Routes in Oregon

Routes recording Orange-crowned Warbler 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 →
Hazel Camp2720221975
Coquille1620241994
Hauser1419851970
Elkton1420241972
Green1220241994
Fisher1120101997
Garfield1020231975
Lorane1020241993
Secret Val920221975
Troy920241992
Harlan 2920242011
Black Mtn.820041996
Klickitat Mt819961993
Desolation819991998
Scappoose720231995
Howard Mdws.620191992
Waldport620011992
Riley Peak620161994
Timber520171968
Wedderburn520241970
Adair520241973
Dayton520221975
Svensen519921990
Granite519891989
Glasgow520241986

Orange-crowned Warbler Population Trend in Other States

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