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

Black-throated Blue Warbler Population Trend in West Virginia

All statesForest birds

Black-throated Blue Warbler in West Virginia has surged: up 17× on the route-weighted index since 1970.

17×Since 1970TrendPercent 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 →
25Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-throated Blue Warbler 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 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 →

Black-throated Blue Warbler has surged in West Virginia: up 17× on the route-weighted index since 1970.

Black-throated Blue Warbler Population Forecast in West Virginia

If the recent trend holds, Black-throated Blue Warbler in West Virginia is projected to stay roughly flat through 2030, near 1.3 (95% range 0.83–1.8). A 5-year backtest shows a typical error of ±21.6%, with 100% of held-out values landing inside the 95% band.

+8%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 →
1.3Projected 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 →
0.83–1.895% 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 →
±21.6%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, Black-throated Blue Warbler in West Virginia is projected to stay roughly flat through 2030, near 1.3 (95% range 0.83–1.8). A 5-year backtest shows a typical error of ±21.6%, 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 →
20261.30.761.8
20271.30.781.8
20281.30.801.8
20291.30.811.8
20301.30.831.8

Black-throated Blue Warbler Survey Routes in West Virginia

Routes recording Black-throated Blue Warbler 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 →
Glade Run 21620252003
Glade Run1320021988
Glady820252003
Richwood820251980
Dailey620251973
Wymer520151995
Bismark520232012
Bowden420251993
Three Forks420251973
Denmar320251990
Green Bank220251979
Pedro120252000
Bramwell119911991
Ghent120242005
Clear Creek120222022
Bemis120242002
Canaan120241974
Valley Head120242005
Mo Of Seneca120121998
Moundsville119741974
Berryburg119811981
Albright119701966
Meadowville120091973
Yellow Spg120232023
Ruthbelle120251977

Black-throated Blue Warbler Population Trend in Other States

connecticutgeorgiamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinapennsylvaniarhode-islandtennesseevermontvirginiawisconsin

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