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Species · Kentucky · BBS 2025 Release · 1966–2024

Worm-eating Warbler Population Trend in Kentucky

All statesForest birds

Worm-eating Warbler in Kentucky has risen sharply: up 69% on the route-weighted index since 1968.

+69%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 →
43Routes 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 →
57YearsYears 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 KentuckyNotable 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 risen sharply in Kentucky: up 69% on the route-weighted index since 1968.

Worm-eating Warbler Population Forecast in Kentucky

If the recent trend holds, Worm-eating Warbler in Kentucky is projected to rise about 247% by 2029 — from 0.29 in 2024 to a central estimate of 0.99 (95% range 0.15–1.8). A 5-year backtest shows a typical error of ±283%, with 20% of held-out values landing inside the 95% band.

+247%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 →
0.99Projected 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 →
0.15–1.895% 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 →
±283%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 Kentucky is projected to rise about 247% by 2029 — from 0.29 in 2024 to a central estimate of 0.99 (95% range 0.15–1.8). A 5-year backtest shows a typical error of ±283%, 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 →
20250.940.101.8
20260.950.121.8
20270.960.131.8
20280.980.141.8
20290.990.151.8

Worm-eating Warbler Survey Routes in Kentucky

Routes recording Worm-eating Warbler in Kentucky.
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 →
Cumberlnd Gp1320181968
Mammoth Cave North1320132009
Mammoth Cave1020141995
Beattyville 2720242006
Pippa Passes419961988
Staffordsvil419971996
Levee 2420192019
Monticello320211969
Levee319801972
Campton320121980
Mckee219761973
Pine Ridge219781966
Phelps219971979
Brownsville120232022
Lovelacevile119891989
Shiloh119941971
Canton120151971
Keysburg119841977
Riverqueen120222022
Dixon120082008
Sulphur Lick119831983
Hegira120231993
Sunnybrook120142014
Bardwell119671967
Apex120232008

Worm-eating Warbler Population Trend in Other States

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

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