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Species · Massachusetts · BBS 2025 Release · 1966–2024

Black-throated Green Warbler Population Trend in Massachusetts

All statesForest birds

Black-throated Green Warbler in Massachusetts has increased: up 32% on the route-weighted index since 1969.

+32%Since 1969TrendPercent 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 →
24Routes 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 →
57YearsYears 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 Green Warbler Trends in MassachusettsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Black-throated Green Warbler in Massachusetts. See the full index history below.

Black-throated Green Warbler Population Forecast in Massachusetts

If the recent trend holds, Black-throated Green Warbler in Massachusetts is projected to rise about 71% by 2029 — from 1.7 in 2024 to a central estimate of 3.0 (95% range 1.7–4.2). A 5-year backtest shows a typical error of ±111.1%, with 0% of held-out values landing inside the 95% band.

+71%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 →
3.0Projected 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 →
1.7–4.295% 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 →
±111.1%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 Massachusetts is projected to rise about 71% by 2029 — from 1.7 in 2024 to a central estimate of 3.0 (95% range 1.7–4.2). A 5-year backtest shows a typical error of ±111.1%, with 0% of held-out values landing inside the 95% band.19672029
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 →
20252.81.64.0
20262.91.64.1
20272.91.74.1
20282.91.74.1
20293.01.74.2

Black-throated Green Warbler Survey Routes in Massachusetts

Routes recording Black-throated Green Warbler in Massachusetts.
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 →
Chesterfield1220241967
Cummington1020141968
Pittsfield920161967
N Orange620241968
Ware River520221993
Monterey420242019
Princeton219761969
Belchertown220241967
N. Andover220041995
Marion119941971
Prattville120151967
Brockton119841984
Newburyport120041967
Maynard120001988
Littleton120001970
E Pepperell119821970
Warren120091969
S Barre120241972
Cheshire119881973
Sheffield120221970
Holden120241977
Warren 2120172011
Cummington 2120232015
Hancock120151998

Black-throated Green Warbler Population Trend in Other States

alabamaarkansasconnecticutgeorgiaindianakentuckymainemarylandmichiganminnesotamissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseevermontvirginiawest-virginiawisconsin

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