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Species · Oregon · BBS 2025 Release · 1966–2024

MacGillivray's Warbler Population Trend in Oregon

All statesForest birds

MacGillivray's Warbler in Oregon has edged down: down 17% on the route-weighted index since 1970.

-17%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 →
102Routes 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 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 rise about 28% by 2029 — from 2.3 in 2024 to a central estimate of 2.9 (95% range 1.6–4.3). A 5-year backtest shows a typical error of ±32.9%, with 100% of held-out values landing inside the 95% band.

+28%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 →
2.9Projected 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 →
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 →
±32.9%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, MacGillivray's Warbler in Oregon is projected to rise about 28% by 2029 — from 2.3 in 2024 to a central estimate of 2.9 (95% range 1.6–4.3). A 5-year backtest shows a typical error of ±32.9%, 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 →
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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 →
Cool Camp1820131968
Black Mtn.1820041993
Lorane1820241993
Picture Flat1720241993
Clearwater1620211991
Logdell1420241971
Donelly 21420242018
Mt Hood1320241972
Summit Pr1220241980
Desolation1220071993
Molalla1220241994
Warner Mtn.1020241992
Ruch1020231992
Klickitat Mt919961993
Hells Canyon820221992
Blue River720241992
Newbridge720241993
Cinderella720241993
Mount Vernon620241986
Ochoco620241993
Lakeview620241996
Wickiup520241969
Days Creek520241970
Secret Val520221975
Troy520241992

MacGillivray's Warbler Population Trend in Other States

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