BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Black-throated Green Warbler In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Black-throated Green Warbler in Appalachian Mountains has surged: up 490% on the route-weighted index since 1968.

+490%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 →
281Routes 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 →
58YearsYears 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 Green Warbler has surged in Appalachian Mountains: up 490% on the route-weighted index since 1968.

Black-throated Green Warbler In Appalachian Mountains Population Forecast

If the recent trend holds, Black-throated Green Warbler in Appalachian Mountains is projected to rise about 29% by 2029 — from 3.4 in 2024 to a central estimate of 4.4 (95% range 3.1–5.7). A 5-year backtest shows a typical error of ±35%, with 60% of held-out values landing inside the 95% band.

+29%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 →
4.4Projected 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 →
3.1–5.795% 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 →
±35%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 Green Warbler in Appalachian Mountains is projected to rise about 29% by 2029 — from 3.4 in 2024 to a central estimate of 4.4 (95% range 3.1–5.7). A 5-year backtest shows a typical error of ±35%, 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 →
20254.12.95.4
20264.22.95.5
20274.33.05.5
20284.33.15.6
20294.43.15.7

Routes In Appalachian Mountains

Routes recording Black-throated Green 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 →
Borden Springs 2ALABAMA302024
MeccaTENNESSEE292023
BemisWEST-VIRGINIA292024
FontanaNORTH-CAROLINA282024
Glade Run 2WEST-VIRGINIA282024
FinzelMARYLAND272024
Newfound GapTENNESSEE272024
WymerWEST-VIRGINIA272015
Table RockNORTH-CAROLINA242022
LynchPENNSYLVANIA242024
McfarlandTENNESSEE221993
HighlandsNORTH-CAROLINA212024
HarbuckTENNESSEE202023
DuboistownPENNSYLVANIA192024
Tussey Mtn.PENNSYLVANIA192024
OdinPENNSYLVANIA182024
St CollegePENNSYLVANIA182024
Cumberlnd GpKENTUCKY172018
RoulettePENNSYLVANIA172021
MunsonPENNSYLVANIA172024
Glade RunWEST-VIRGINIA172002
RidgwayPENNSYLVANIA162018
EllentonPENNSYLVANIA162024
Russell CityPENNSYLVANIA152024
Roulette 2PENNSYLVANIA152024

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