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Species · Alabama · BBS 2025 Release · 1966–2024

Worm-eating Warbler Population Trend in Alabama

All statesForest birds

Worm-eating Warbler in Alabama has surged: up 346% on the route-weighted index since 1968.

+346%Since 1968TrendPercent 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 →
61Routes 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 →
58YearsYears 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 AlabamaNotable 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 →

Worm-eating Warbler has surged in Alabama: up 346% on the route-weighted index since 1968.

Worm-eating Warbler Population Forecast in Alabama

If the recent trend holds, Worm-eating Warbler in Alabama is projected to rise about 49% by 2029 — from 0.32 in 2024 to a central estimate of 0.47 (95% range 0.28–0.66). A 5-year backtest shows a typical error of ±67%, with 20% of held-out values landing inside the 95% band.

+49%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 →
0.47Projected 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 →
0.28–0.6695% 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%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 Alabama is projected to rise about 49% by 2029 — from 0.32 in 2024 to a central estimate of 0.47 (95% range 0.28–0.66). A 5-year backtest shows a typical error of ±67%, with 20% of held-out values landing inside the 95% band.19662029
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 →
20250.450.260.63
20260.450.270.64
20270.460.270.64
20280.460.280.65
20290.470.280.66

Worm-eating Warbler Survey Routes in Alabama

Routes recording Worm-eating Warbler in Alabama.
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 →
Borden Springs 2520242001
Holt420241995
Nixburg419991996
Oneonta420232009
Beatrice320051969
Linden220231997
Millry219921970
Epes220241992
Escatawpa220161988
Grove Hill220231983
Youngtown220211994
Wheeler Dam220072007
Elkmont219991993
Woodville220221994
Vina220231996
Talladega220242000
Gastonburg220022002
Brooksville220182005
St Florian119941988
Hillsboro119961972
Trade120142014
Valhermoso Spgs119821982
Swaim120191979
Pine Grove120171987
Dawson119891966

Worm-eating Warbler Population Trend in Other States

arkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckylouisianamarylandmassachusettsmississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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