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Species · Virginia · BBS 2026 Release · 1966–2025

Worm-eating Warbler Population Trend in Virginia

All statesForest birds

Worm-eating Warbler in Virginia has surged: up 338% on the route-weighted index since 1968.

+338%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 →
72Routes 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 →
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 Worm-eating Warbler Trends in VirginiaNotable 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 Virginia: up 338% on the route-weighted index since 1968.

Worm-eating Warbler Population Forecast in Virginia

If the recent trend holds, Worm-eating Warbler in Virginia is projected to rise about 55% by 2030 — from 1.6 in 2025 to a central estimate of 2.5 (95% range 1.6–3.3). A 5-year backtest shows a typical error of ±31.1%, with 60% of held-out values landing inside the 95% band.

+55%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 →
2.5Projected 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 →
1.6–3.395% 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 →
±31.1%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 Virginia is projected to rise about 55% by 2030 — from 1.6 in 2025 to a central estimate of 2.5 (95% range 1.6–3.3). A 5-year backtest shows a typical error of ±31.1%, with 60% 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 →
20262.31.53.2
20272.31.53.2
20282.41.53.2
20292.41.63.3
20302.51.63.3

Worm-eating Warbler Survey Routes in Virginia

Routes recording Worm-eating Warbler in Virginia.
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 →
Front Royal1120251993
Covington920251966
Gr North Mtn820251993
Glenwood820231992
Shenandoa Np820221994
Douthat720121992
Rural Retrt620251982
Marion619821977
W Augusta520251967
Edinburg520251969
Bald Knob520251992
Iron Mtn.520071998
Stanley420251969
Truhart420241996
Amherst320251993
Covesville320251971
Dismal Swamp320161992
Loft Mtn320231993
Potts Mtn.320131992
Big Meadows320251993
Carters Brdg 2320232015
Jerome220251978
Shipman220251984
Concord220242024
Mannboro220191985

Worm-eating Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckylouisianamarylandmassachusettsmississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexaswest-virginiawisconsin

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