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

Black-throated Blue Warbler Population Trend in Virginia

All statesForest birds

Black-throated Blue Warbler in Virginia has risen sharply: up 56% on the route-weighted index since 1968.

+56%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 →
50YearsYears 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 risen sharply in Virginia: up 56% 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 173% by 2030 — from 0.21 in 2025 to a central estimate of 0.57 (95% range 0.21–0.92). A 5-year backtest shows a typical error of ±109.8%, with 60% of held-out values landing inside the 95% band.

+173%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 →
0.57Projected 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 →
0.21–0.9295% 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 →
±109.8%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 173% by 2030 — from 0.21 in 2025 to a central estimate of 0.57 (95% range 0.21–0.92). A 5-year backtest shows a typical error of ±109.8%, 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 →
20260.540.180.89
20270.540.190.90
20280.550.200.91
20290.560.200.91
20300.570.210.92

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 Augusta520251967
Covington220251966
Clinchport219691969
Bald Knob120251994
Gr North Mtn120242021
Rural Retrt120251987
Shenandoa Np119941994
Putnam119921992
Fincastle119671967
Shipman119731972
Loft Mtn120111994
Front Royal120182002
Saltville120251984
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 2026-08-14.