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Species · Oregon · BBS 2025 Release · 1966–2024

Swainson's Thrush Population Trend in Oregon

All statesForest birds

Swainson's Thrush in Oregon has declined: down 28% on the route-weighted index since 1970.

-28%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 →
87Routes 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 Swainson's 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 →

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

Swainson's Thrush Population Forecast in Oregon

If the recent trend holds, Swainson's Thrush in Oregon is projected to rise about 31% by 2029 — from 11 in 2024 to a central estimate of 15 (95% range 8.8–20). A 5-year backtest shows a typical error of ±20.7%, with 100% of held-out values landing inside the 95% band.

+31%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 →
15Projected 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 →
8.8–2095% 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 →
±20.7%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, Swainson's Thrush in Oregon is projected to rise about 31% by 2029 — from 11 in 2024 to a central estimate of 15 (95% range 8.8–20). A 5-year backtest shows a typical error of ±20.7%, 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 →
2025148.520
2026148.620
2027148.720
2028148.720
2029158.820

Swainson's Thrush Survey Routes in Oregon

Routes recording Swainson's 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 →
Fisher27020101997
Klickitat Mt13919961993
Trask Summit10420241992
Coquille9520241994
Santiam9120241994
Harlan8720092006
Salado8220241968
Riley Peak8220161994
Nicolai Mtn.7220241993
Clearwater6820211991
Molalla6520241994
Fisher 26520242017
Wedderburn5820241970
Lorane5720241993
Hauser5219851970
Cool Camp4420131968
Harlan 24320242011
Glasgow4020241986
Timber3820171968
Winberry3820231968
Bull Run3720242007
Elkton3620241972
Waldport3620011992
Sandy River3020061993
Svensen2719921990

Swainson's Thrush Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahoillinoismainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinapennsylvaniasouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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