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Species · Massachusetts · BBS 2025 Release · 1966–2024

Wood Thrush Population Trend in Massachusetts

All statesForest birds

Wood Thrush in Massachusetts has fallen sharply: down 66% on the route-weighted index since 1968.

-66%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 →
30Routes 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 →
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 Wood Thrush 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 declinecomputed 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 →

Wood Thrush has fallen sharply in Massachusetts: down 66% on the route-weighted index since 1968.

Wood Thrush Population Forecast in Massachusetts

If the recent trend holds, Wood Thrush in Massachusetts is projected to fall about 76% by 2029 — from 3.5 in 2024 to a central estimate of 0.83 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±42.9%, with 100% of held-out values landing inside the 95% band.

-76%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 →
0.83Projected 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 →
0.00–5.395% 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 →
±42.9%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, Wood Thrush in Massachusetts is projected to fall about 76% by 2029 — from 3.5 in 2024 to a central estimate of 0.83 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±42.9%, with 100% 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 →
20251.90.006.4
20261.60.006.1
20271.30.005.8
20281.10.005.6
20290.830.005.3

Wood Thrush Survey Routes in Massachusetts

Routes recording Wood Thrush 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 →
Cummington1720141968
Princeton1519761969
Pittsfield1420161967
Belchertown1120241967
Cummington 21020242015
Hancock920151997
N Oxford720241968
Warren620091968
Cheshire619941969
S Barre520241968
Warren 2520242010
Sheffield420221969
Brockton320161967
N Orange320241968
Holden320241977
Chilmark219831969
Wellfleet219961970
Newburyport220211967
Chesterfield220241967
Monterey220242019
E Dennis120041967
Marion120241966
Prattville120181966
Maynard120211967
Littleton120241967

Wood Thrush Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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