BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Swainson's Thrush In Great Basin

All regionsGreat BasinForest birds

Swainson's Thrush in Great Basin has declined: down 34% on the route-weighted index since 1970.

-34%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 →
67Routes In RegionSurvey 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 SignalsNotable 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 Great Basin. See the full index history below.

Swainson's Thrush In Great Basin Population Forecast

If the recent trend holds, Swainson's Thrush in Great Basin is projected to rise about 23% by 2030 — from 2.5 in 2025 to a central estimate of 3.0 (95% range 1.6–4.5). A 5-year backtest shows a typical error of ±14.3%, with 100% of held-out values landing inside the 95% band.

+23%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 →
1.6–4.595% 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 →
±14.3%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, Swainson's Thrush in Great Basin is projected to rise about 23% by 2030 — from 2.5 in 2025 to a central estimate of 3.0 (95% range 1.6–4.5). A 5-year backtest shows a typical error of ±14.3%, 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 →
20263.01.64.4
20273.01.64.4
20283.01.64.5
20293.01.64.5
20303.01.64.5

Routes In Great Basin

Routes recording Swainson's Thrush in Great Basin.
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 →
KendallWASHINGTON782025
ConcreteWASHINGTON552025
NewhalemWASHINGTON532025
IndexWASHINGTON491971
L. WenatcheeWASHINGTON452025
Index 2WASHINGTON412023
Suiattle RivWASHINGTON382019
GlacierWASHINGTON352024
IndexWASHINGTON351997
CarltonWASHINGTON292022
White ChuckWASHINGTON272025
Cascade RivWASHINGTON252006
HyrumUTAH171979
WinthropWASHINGTON162022
LeavenworthWASHINGTON162024
JarbidgeNEVADA142015
RimrockWASHINGTON142025
Blewett PassWASHINGTON142025
No CascadesWASHINGTON142019
Silver CityIDAHO102014
Magic MtnIDAHO92025
MazamaWASHINGTON92022
Dinner StaNEVADA71968
Mt HoodOREGON72025
RonaldWASHINGTON72025

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