BirdAnalyst
Species · BCR 24 · BBS 2026 Release · 1966–2025

Worm-eating Warbler In Central Hardwoods

All regionsCentral HardwoodsForest birds

Worm-eating Warbler in Central Hardwoods has surged: up 169% on the route-weighted index since 1968.

+169%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 →
102Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Central Hardwoods: up 169% on the route-weighted index since 1968.

Worm-eating Warbler In Central Hardwoods Population Forecast

If the recent trend holds, Worm-eating Warbler in Central Hardwoods is projected to rise about 100% by 2030 — from 0.39 in 2025 to a central estimate of 0.79 (95% range 0.39–1.2). A 5-year backtest shows a typical error of ±134.9%, with 0% of held-out values landing inside the 95% band.

+100%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 →
0.79Projected 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 →
0.39–1.295% 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 →
±134.9%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 Central Hardwoods is projected to rise about 100% by 2030 — from 0.39 in 2025 to a central estimate of 0.79 (95% range 0.39–1.2). A 5-year backtest shows a typical error of ±134.9%, with 0% 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 →
20260.750.351.1
20270.760.361.2
20280.770.371.2
20290.780.381.2
20300.790.391.2

Routes In Central Hardwoods

Routes recording Worm-eating Warbler in Central Hardwoods.
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 →
Mammoth Cave NorthKENTUCKY132013
HoosierINDIANA122025
Mammoth CaveKENTUCKY102014
MarshallARKANSAS52021
ClementineMISSOURI51996
Ozark NfARKANSAS42025
Levee 2KENTUCKY42019
CascadeMISSOURI42023
CentervilleMISSOURI42025
TullahomaTENNESSEE42015
RupertARKANSAS32018
AvocaARKANSAS31967
LeveeKENTUCKY31980
IrontonMISSOURI31980
Lewis ForestTENNESSEE32024
Wheeler DamALABAMA22007
ElkmontALABAMA21999
ZionARKANSAS22025
CelestineINDIANA22019
ApexKENTUCKY22025
Clementine 2MISSOURI22007
Pond CreekTENNESSEE22025
Indian MoundTENNESSEE21987
WrigleyTENNESSEE22022
BradyvilleTENNESSEE22004

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