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Species · Oregon · BBS 2026 Release · 1966–2025

MacGillivray's Warbler Population Trend in Oregon

All statesForest birds

MacGillivray's Warbler in Oregon has held roughly steady: down 6% on the route-weighted index since 1970.

-6%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 →
103Routes 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 MacGillivray's 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 →

No notable trend signals for MacGillivray's Warbler in Oregon. See the full index history below.

MacGillivray's Warbler Population Forecast in Oregon

If the recent trend holds, MacGillivray's Warbler in Oregon is projected to stay roughly flat through 2030, near 3.0 (95% range 1.6–4.3). A 5-year backtest shows a typical error of ±26.3%, with 100% of held-out values landing inside the 95% band.

-4%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 →
3.0Projected 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 →
1.6–4.395% 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 →
±26.3%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, MacGillivray's Warbler in Oregon is projected to stay roughly flat through 2030, near 3.0 (95% range 1.6–4.3). A 5-year backtest shows a typical error of ±26.3%, 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 →
20262.91.64.3
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20293.01.64.3
20303.01.64.3

MacGillivray's Warbler Survey Routes in Oregon

Routes recording MacGillivray's 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 →
Wallowa3320252025
Hells Canyon2220251992
Logdell1920251971
Cool Camp1820131968
Black Mtn.1820041993
Eagle Creek1620251993
Lorane1620251993
Donelly 21620252018
Mt Hood1420251972
Newbridge1420251993
Ochoco1220251993
Picture Flat1220251993
Desolation1120251993
Days Creek1020251970
Ruch1020231992
Wizard Falls920251998
Klickitat Mt919961993
Secret Val820251975
Hash Rock820251988
Selma820251993
Summit Pr720251980
Troy720251992
Wickiup620251969
Mount Vernon620241986
Lakeview620251996

MacGillivray's Warbler Population Trend in Other States

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