BirdAnalyst
Species · BCR 29 · BBS 2026 Release · 1966–2025

Worm-eating Warbler In Piedmont

All regionsPiedmontForest birds

Worm-eating Warbler in Piedmont has surged: up 121% on the route-weighted index since 1969.

+121%Since 1969TrendPercent 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 →
66Routes 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 →
53YearsYears 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 Piedmont: up 121% on the route-weighted index since 1969.

Worm-eating Warbler In Piedmont Population Forecast

If the recent trend holds, Worm-eating Warbler in Piedmont is projected to rise about 12% by 2030 — from 0.17 in 2025 to a central estimate of 0.20 (95% range 0.10–0.29). A 5-year backtest shows a typical error of ±17.7%, with 100% of held-out values landing inside the 95% band.

+12%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 →
0.10–0.2995% 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 →
±17.7%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 Piedmont is projected to rise about 12% by 2030 — from 0.17 in 2025 to a central estimate of 0.20 (95% range 0.10–0.29). A 5-year backtest shows a typical error of ±17.7%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.190.090.28
20270.190.090.29
20280.190.090.29
20290.190.100.29
20300.200.100.29

Routes In Piedmont

Routes recording Worm-eating Warbler in Piedmont.
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 →
NixburgALABAMA41999
EkloMARYLAND42017
OwingsSOUTH-CAROLINA42000
EarltonMARYLAND32024
AmherstVIRGINIA32025
CovesvilleVIRGINIA32025
Carters Brdg 2VIRGINIA32023
AthensGEORGIA22025
Piedmont NwrGEORGIA21995
Van BibberMARYLAND22013
MadonnaMARYLAND22017
EdenNORTH-CAROLINA22018
SchwenksvillPENNSYLVANIA22002
ShipmanVIRGINIA22025
ConcordVIRGINIA22024
MannboroVIRGINIA22019
MillervilleALABAMA12012
Liberty City 2ALABAMA12022
Nixburg 2ALABAMA12013
WedoweeALABAMA12023
BaldwinGEORGIA12022
BowdonGEORGIA12008
HiramGEORGIA11987
WashingtonGEORGIA11989
WhitesburgGEORGIA12001

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