BirdAnalyst
Species · South Carolina · BBS 2025 Release · 1966–2024

Worm-eating Warbler Population Trend in South Carolina

All statesForest birds

Worm-eating Warbler in South Carolina has declined: down 47% on the route-weighted index since 1996.

-47%Since 1996TrendPercent 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 →
8Routes 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 →
21YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Worm-eating Warbler Trends in South CarolinaNotable 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 Worm-eating Warbler in South Carolina. See the full index history below.

Worm-eating Warbler Population Forecast in South Carolina

If the recent trend holds, Worm-eating Warbler in South Carolina is projected to stay roughly flat through 2029, near 0.12 (95% range 0.00–0.37). A 5-year backtest shows a typical error of ±125.3%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.12Projected 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 →
0.00–0.3795% 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 →
±125.3%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, Worm-eating Warbler in South Carolina is projected to stay roughly flat through 2029, near 0.12 (95% range 0.00–0.37). A 5-year backtest shows a typical error of ±125.3%, with 80% of held-out values landing inside the 95% band.19812029
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 →
20250.120.000.37
20260.120.000.37
20270.120.000.37
20280.120.000.37
20290.120.000.37

Worm-eating Warbler Survey Routes in South Carolina

Routes recording Worm-eating Warbler in South Carolina.
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 →
Battlecreek1520141999
Owings420001999
Jamestown120051996
Adams Run120172009
Coward119811981
Prosperity120122000
Plum Branch120241993
Salem120192019

Worm-eating Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckylouisianamarylandmassachusettsmississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandtennesseetexasvirginiawest-virginiawisconsin

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