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Species · Virginia · BBS 2025 Release · 1966–2024

Black-throated Blue Warbler Population Trend in Virginia

All statesForest birds

Black-throated Blue Warbler in Virginia has surged: up 99% on the route-weighted index since 1968.

+99%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 →
20Routes 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 →
49YearsYears 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 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 Virginia: up 99% on the route-weighted index since 1968.

Black-throated Blue Warbler Population Forecast in Virginia

If the recent trend holds, Black-throated Blue Warbler in Virginia is projected to rise about 238% by 2029 — from 0.17 in 2024 to a central estimate of 0.58 (95% range 0.24–0.93). A 5-year backtest shows a typical error of ±166.8%, with 60% of held-out values landing inside the 95% band.

+238%Change by 2029TrendPercent 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 →
0.58Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.24–0.9395% 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 →
±166.8%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, Black-throated Blue Warbler in Virginia is projected to rise about 238% by 2029 — from 0.17 in 2024 to a central estimate of 0.58 (95% range 0.24–0.93). A 5-year backtest shows a typical error of ±166.8%, with 60% of held-out values landing inside the 95% band.19662029
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 →
20250.550.210.90
20260.560.210.91
20270.570.220.91
20280.580.230.92
20290.580.240.93

Black-throated Blue Warbler Survey Routes in Virginia

Routes recording Black-throated Blue 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 →
Mountain Lk.2120181992
Iron Mountain 21220132012
Iron Mountain 31220232014
Iron Mtn.920111992
Marion619821976
W Augusta520241967
Bald Knob320241994
Covington320231966
Clinchport219691969
Gr North Mtn120242021
Rural Retrt120171987
Shenandoa Np119941994
Putnam119921992
Fincastle119671967
Shipman119731972
Loft Mtn120111994
Front Royal120182002
Saltville120221984
Elamsville120141992
Hebron119811981

Black-throated Blue Warbler Population Trend in Other States

connecticutgeorgiamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinapennsylvaniarhode-islandtennesseevermontwest-virginiawisconsin

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.