BirdAnalyst
Species · BCR 28 · BBS 2026 Release · 1966–2025

Black-throated Blue Warbler In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Black-throated Blue Warbler in Appalachian Mountains has surged: up 761% on the route-weighted index since 1968.

+761%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 →
183Routes In RegionSurvey 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 SignalsNotable 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 Appalachian Mountains: up 761% on the route-weighted index since 1968.

Black-throated Blue Warbler In Appalachian Mountains Population Forecast

If the recent trend holds, Black-throated Blue Warbler in Appalachian Mountains is projected to rise about 35% by 2030 — from 1.2 in 2025 to a central estimate of 1.6 (95% range 1.3–1.9). A 5-year backtest shows a typical error of ±16.2%, with 60% of held-out values landing inside the 95% band.

+35%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 →
1.6Projected 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 →
1.3–1.995% 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 →
±16.2%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 Appalachian Mountains is projected to rise about 35% by 2030 — from 1.2 in 2025 to a central estimate of 1.6 (95% range 1.3–1.9). A 5-year backtest shows a typical error of ±16.2%, 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 →
20261.51.21.8
20271.51.21.8
20281.51.21.8
20291.61.31.9
20301.61.31.9

Routes In Appalachian Mountains

Routes recording Black-throated Blue Warbler in Appalachian Mountains.
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 →
KyleNORTH-CAROLINA342024
N. Mills RivNORTH-CAROLINA251995
Mountain Lk.VIRGINIA212018
LinvilleNORTH-CAROLINA182025
Glade Run 2WEST-VIRGINIA162025
French Broad RiverNORTH-CAROLINA152025
LynchPENNSYLVANIA142025
Glade RunWEST-VIRGINIA132002
Iron Mountain 2VIRGINIA122013
Iron Mountain 3VIRGINIA122023
AndrewsNORTH-CAROLINA101998
CherokeeNORTH-CAROLINA102025
JenningsMARYLAND92025
Broad Mtn.PENNSYLVANIA92025
McfarlandTENNESSEE91986
Newfound GapTENNESSEE92025
Iron Mtn.VIRGINIA92011
Laurel HillPENNSYLVANIA82025
RichwoodWEST-VIRGINIA82025
GladyWEST-VIRGINIA82025
OdinPENNSYLVANIA72025
Ltl Pine CrPENNSYLVANIA72025
CullowheeNORTH-CAROLINA62025
N Pine GrovePENNSYLVANIA62025
TellicoTENNESSEE62025

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