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Species · Mississippi · BBS 2026 Release · 1966–2025

Swainson's Warbler Population Trend in Mississippi

All statesForest birds

Swainson's Warbler in Mississippi has risen sharply: up 53% on the route-weighted index since 1974.

+53%Since 1974TrendPercent 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 →
34Routes 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 →
45YearsYears 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 MississippiNotable 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 Warbler has risen sharply in Mississippi: up 53% on the route-weighted index since 1974.

Swainson's Warbler Population Forecast in Mississippi

If the recent trend holds, Swainson's Warbler in Mississippi is projected to fall about 26% by 2030 — from 0.26 in 2025 to a central estimate of 0.20 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±67.6%, with 100% of held-out values landing inside the 95% band.

-26%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 →
0.20Projected 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 →
0.00–0.4795% 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 →
±67.6%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 Mississippi is projected to fall about 26% by 2030 — from 0.26 in 2025 to a central estimate of 0.20 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±67.6%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.200.000.47
20270.200.000.47
20280.200.000.47
20290.200.000.47
20300.200.000.47

Swainson's Warbler Survey Routes in Mississippi

Routes recording Swainson's Warbler in Mississippi.
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 →
Trace Lorman520192016
Trace Attala320192016
Columbia320181974
Benndale319901978
Trace South320192010
Trace North320082008
Lake Mary219771976
Fayette220041980
Forest220231972
Lake220251972
Trace Chickasaw220232014
Star220242019
Monticello220072007
Embry220251990
Beverly119931966
Lake Como120142014
Benton119721972
Delta N.F.120081996
Utica120161978
Lucien119791974
Grenada Lake120192016
Walthall119781978
Trace Hinds120192014
Trace Choctaw120192018
Corinth120251974

Swainson's Warbler Population Trend in Other States

alabamaarkansasfloridageorgiakentuckylouisianamarylandnorth-carolinaoklahomasouth-carolinatennesseetexasvirginiawest-virginia

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