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Species · BCR 14 · BBS 2025 Release · 1966–2024

Black-throated Green Warbler In Atlantic Northern Forest

All regionsAtlantic Northern ForestForest birds

Black-throated Green Warbler in Atlantic Northern Forest has surged: up 139% on the route-weighted index since 1968.

+139%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 →
155Routes 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 Atlantic Northern Forest: up 139% on the route-weighted index since 1968.

Black-throated Green Warbler In Atlantic Northern Forest Population Forecast

If the recent trend holds, Black-throated Green Warbler in Atlantic Northern Forest is projected to rise about 64% by 2029 — from 4.0 in 2024 to a central estimate of 6.6 (95% range 4.4–8.8). A 5-year backtest shows a typical error of ±77%, with 0% of held-out values landing inside the 95% band.

+64%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 →
6.6Projected 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 →
4.4–8.895% 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 →
±77%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 Atlantic Northern Forest is projected to rise about 64% by 2029 — from 4.0 in 2024 to a central estimate of 6.6 (95% range 4.4–8.8). A 5-year backtest shows a typical error of ±77%, with 0% 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 →
20256.34.18.6
20266.44.28.6
20276.54.28.7
20286.54.38.8
20296.64.48.8

Routes In Atlantic Northern Forest

Routes recording Black-throated Green Warbler in Atlantic Northern Forest.
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 →
NorthfieldMAINE851981
InletNEW-YORK322017
CooperMAINE302021
WaiteMAINE271977
EastbrookMAINE242024
Old ForgeNEW-YORK232006
Wilson MillsMAINE212024
SabattisNEW-YORK211983
Seboomook LkMAINE202014
Blue Ridge SNEW-YORK172010
BrooksMAINE162019
NesowadnehunMAINE152021
Dixvil NotchNEW-HAMPSHIRE152017
Dexter LakeNEW-YORK151975
Old Forge 2NEW-YORK152019
Grnd Lk StrmMAINE132000
AndoverMAINE132021
Dixville Notch 2NEW-HAMPSHIRE132024
StoweVERMONT132024
ChesterfieldMASSACHUSETTS122024
MedwayMAINE112018
TopsfieldMAINE111996
ClarksvilleNEW-HAMPSHIRE112024
CummingtonMASSACHUSETTS102014
PittsfieldMASSACHUSETTS92016

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