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Species · Montana · BBS 2025 Release · 1966–2024

Swainson's Thrush Population Trend in Montana

All statesForest birds

Swainson's Thrush in Montana has surged: up 163% on the route-weighted index since 1970.

+163%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 →
45Routes 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 MontanaNotable 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 increasecomputed 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 →

Swainson's Thrush has surged in Montana: up 163% on the route-weighted index since 1970.

Swainson's Thrush Population Forecast in Montana

If the recent trend holds, Swainson's Thrush in Montana is projected to rise about 12% by 2029 — from 8.9 in 2024 to a central estimate of 9.9 (95% range 7.4–12). A 5-year backtest shows a typical error of ±9.5%, with 100% of held-out values landing inside the 95% band.

+12%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 →
9.9Projected 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 →
7.4–1295% 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 →
±9.5%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, Swainson's Thrush in Montana is projected to rise about 12% by 2029 — from 8.9 in 2024 to a central estimate of 9.9 (95% range 7.4–12). A 5-year backtest shows a typical error of ±9.5%, 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 →
20259.57.012
20269.67.112
20279.77.212
20289.87.312
20299.97.412

Swainson's Thrush Survey Routes in Montana

Routes recording Swainson's Thrush in Montana.
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 Lake9820242016
Swan Lake7920242015
Libby Dam7620241979
Thompson Riv7620241993
Noxon6120231995
Fish Creek5520241995
Inside Road4620241990
Skalkaho4519981992
St Regis4320241977
Logan Pass3520241980
Woodman3520241968
Greenoagh 33420242012
Arlee3320241969
Elevation Mt2820241996
Cramer Creek2520191994
Ninemile2420241993
Painted Rock2220221992
Skalkho-Rye2020221999
Greenoagh 22020112005
Threemile Wa1920241993
Greenough1320041995
Clinton1320241975
Clancy1120232015
Victor920241993
Sula920241978

Swainson's Thrush Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahoillinoismainemarylandmassachusettsmichiganminnesotanebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinaoregonpennsylvaniasouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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