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Species · Massachusetts · BBS 2026 Release · 1966–2025

Pine Warbler Population Trend in Massachusetts

All statesForest birds

Pine Warbler in Massachusetts has surged: up 549% on the route-weighted index since 1968.

+549%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 →
28Routes 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 →
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 Pine 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 →

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 →

Pine Warbler has surged in Massachusetts: up 549% on the route-weighted index since 1968.

Pine Warbler Population Forecast in Massachusetts

If the recent trend holds, Pine Warbler in Massachusetts is projected to stay roughly flat through 2030, near 12 (95% range 8.5–16). A 5-year backtest shows a typical error of ±13.4%, with 100% of held-out values landing inside the 95% band.

-9%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 →
12Projected 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 →
8.5–1695% 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 →
±13.4%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, Pine Warbler in Massachusetts is projected to stay roughly flat through 2030, near 12 (95% range 8.5–16). A 5-year backtest shows a typical error of ±13.4%, with 100% 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 →
2026117.715
2027127.915
2028128.116
2029128.316
2030128.516

Pine Warbler Survey Routes in Massachusetts

Routes recording Pine 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 →
Wellfleet 25920252016
Marion2920251970
Cape Cod Ns2420071989
Ware River2320221993
N Orange2020251980
Maynard1920251988
Prattville1720191966
Belchertown1420251977
Holden1120251978
N. Andover1120251995
Cummington 21020252018
Mansfield920251990
S Barre920251983
Gay Head720251996
Brockton620191990
N Oxford620252004
Wellfleet520071966
Warren520091976
Monterey520252019
Chilmark419831971
Newburyport420221993
Chesterfield420252002
Sheffield320222005
Littleton220251978
Warren 2220252010

Pine Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamainemarylandmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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