BirdAnalyst
Species · West Virginia · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in West Virginia

All statesForest birds

Warbling Vireo in West Virginia has collapsed: down 76% on the route-weighted index since 1968.

-76%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 →
53Routes 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 Warbling Vireo Trends in West 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 declinecomputed 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 →

Warbling Vireo has collapsed in West Virginia: down 76% on the route-weighted index since 1968.

Warbling Vireo Population Forecast in West Virginia

If the recent trend holds, Warbling Vireo in West Virginia is projected to fall about 43% by 2030 — from 0.51 in 2025 to a central estimate of 0.29 (95% range 0.00–0.89). A 5-year backtest shows a typical error of ±21.8%, with 100% of held-out values landing inside the 95% band.

-43%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 →
0.29Projected 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 →
0.00–0.8995% 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 →
±21.8%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, Warbling Vireo in West Virginia is projected to fall about 43% by 2030 — from 0.51 in 2025 to a central estimate of 0.29 (95% range 0.00–0.89). A 5-year backtest shows a typical error of ±21.8%, with 100% 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 →
20260.380.000.98
20270.360.000.96
20280.340.000.93
20290.310.000.91
20300.290.000.89

Warbling Vireo Survey Routes in West Virginia

Routes recording Warbling Vireo in West 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 →
Martinsburg920251966
Yellow Spg620221972
Moundsville420251972
Clendenin319861979
Lost River320252006
Wymer220142000
Olcott219751966
Mcdonald220171987
Berryburg219941975
Josephs Mill220231995
Hix120251997
Smoot120212021
Glade Run119991988
Bowden120072007
Hanover120172017
Welch120172017
Glady120052005
Pt Pleasant120251973
Arlee119751969
Hubbardstown120041967
Spencer120241986
Nicut120211986
Meadland120251997
Bemis120162016
Paradise120231966

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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