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Species · BCR 10 · BBS 2025 Release · 1966–2024

Swainson's Thrush In Northern Rockies

All regionsNorthern RockiesForest birds

Swainson's Thrush in Northern Rockies has increased: up 49% on the route-weighted index since 1970.

+49%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 →
131Routes 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 →
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 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 Northern Rockies. See the full index history below.

Forecast

If the recent trend holds, Swainson's Thrush in Northern Rockies is projected to rise about 43% by 2029 — from 8.4 in 2024 to a central estimate of 12 (95% range 8.7–15). A 5-year backtest shows a typical error of ±15.2%, with 80% of held-out values landing inside the 95% band.

+43%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 →
12Projected 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 →
8.7–1595% 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 →
±15.2%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 Northern Rockies is projected to rise about 43% by 2029 — from 8.4 in 2024 to a central estimate of 12 (95% range 8.7–15). A 5-year backtest shows a typical error of ±15.2%, with 80% 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 →
2025128.215
2026128.415
2027128.515
2028128.615
2029128.715

Routes In Northern Rockies

Routes recording Swainson's Thrush in Northern Rockies.
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 →
Whitefish LakeMONTANA982024
Lolo PassIDAHO962019
Swan LakeMONTANA792024
Libby DamMONTANA762024
Thompson RivMONTANA762024
AveryIDAHO632023
Rochat DivdeIDAHO612023
NoxonMONTANA612023
Sullivan Lake 2WASHINGTON602024
Fish CreekMONTANA552024
PierceIDAHO532007
GrangevilleIDAHO482024
Inside RoadMONTANA462024
SkalkahoMONTANA451998
Deep CreekIDAHO441985
St RegisMONTANA432024
Marble CreekIDAHO392023
N Fork Cda RIDAHO362019
Twin LakesWASHINGTON362024
Sullivan LkWASHINGTON361999
Colter Bay 2WYOMING362024
WoodmanMONTANA352024
Logan PassMONTANA352024
L Pend O NwrWASHINGTON352024
Greenoagh 3MONTANA342024

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