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Species · Oregon · BBS 2025 Release · 1966–2024

Varied Thrush Population Trend in Oregon

All statesForest birds

Varied Thrush in Oregon has fallen sharply: down 62% on the route-weighted index since 1970.

-62%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 →
55Routes 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 Varied Thrush 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 →

Varied Thrush has fallen sharply in Oregon: down 62% on the route-weighted index since 1970.

Varied Thrush Population Forecast in Oregon

If the recent trend holds, Varied Thrush in Oregon is projected to rise about 209% by 2029 — from 0.72 in 2024 to a central estimate of 2.2 (95% range 0.60–3.8). A 5-year backtest shows a typical error of ±156.5%, with 60% of held-out values landing inside the 95% band.

+209%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 →
2.2Projected 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 →
0.60–3.895% 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 →
±156.5%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, Varied Thrush in Oregon is projected to rise about 209% by 2029 — from 0.72 in 2024 to a central estimate of 2.2 (95% range 0.60–3.8). A 5-year backtest shows a typical error of ±156.5%, with 60% 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 →
20252.20.543.8
20262.20.553.8
20272.20.573.8
20282.20.583.8
20292.20.603.8

Varied Thrush Survey Routes in Oregon

Routes recording Varied Thrush 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 →
Klickitat Mt2619961993
Cool Camp2220131968
Waldport2120011992
Santiam2020241994
Fisher2020101997
Riley Peak1920161994
Myrtle Grove1420231992
Trask Summit1220241992
Clearwater1120211993
Nicolai Mtn.1020241993
Svensen919921990
Harlan820092007
Cinderella820241993
Warner Mtn.620241992
Joseph519841982
Molalla420231994
Winberry420211968
Fisher 2420242017
Blue River420241992
Shellrock320231968
Wedderburn320212021
Scio320041972
Sandy River219991993
Scappoose220132013
Harlan 2220242011

Varied Thrush Population Trend in Other States

alaskacaliforniaidahomontanawashington

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