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Species · Tennessee · BBS 2026 Release · 1966–2025

Swainson's Warbler Population Trend in Tennessee

All statesForest birds

Swainson's Warbler in Tennessee has surged: up 21× on the route-weighted index since 1972.

21×Since 1972TrendPercent 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 →
16Routes 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 →
44YearsYears 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 Warbler Trends in TennesseeNotable 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 Warbler in Tennessee. See the full index history below.

Swainson's Warbler Population Forecast in Tennessee

If the recent trend holds, Swainson's Warbler in Tennessee is projected to fall about 32% by 2030 — from 0.55 in 2025 to a central estimate of 0.37 (95% range 0.13–0.61). A 5-year backtest shows a typical error of ±57.7%, with 20% of held-out values landing inside the 95% band.

-32%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 →
0.37Projected 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 →
0.13–0.6195% 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 →
±57.7%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 Warbler in Tennessee is projected to fall about 32% by 2030 — from 0.55 in 2025 to a central estimate of 0.37 (95% range 0.13–0.61). A 5-year backtest shows a typical error of ±57.7%, with 20% of held-out values landing inside the 95% band.19672030
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 →
20260.340.100.58
20270.350.110.59
20280.360.110.60
20290.360.120.61
20300.370.130.61

Swainson's Warbler Survey Routes in Tennessee

Routes recording Swainson's Warbler in Tennessee.
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 →
Smokey Jct420221978
Willis Sprng420231994
Mcfarland319761972
Mansfield320252009
Tellico320251995
Silerton220241992
Fish Springs220221998
Cornpone220242024
Elk Valley220251975
Tiptonville120131992
Oliver Spgs120182006
Mecca120231999
Whiteville120251967
Harbuck120232023
Humboldt120251970
Cades Cove120252019

Swainson's Warbler Population Trend in Other States

alabamaarkansasfloridageorgiakentuckylouisianamarylandmississippinorth-carolinaoklahomasouth-carolinatexasvirginiawest-virginia

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