BirdAnalyst
Species · Massachusetts · BBS 2026 Release · 1966–2025

Wood Thrush Population Trend in Massachusetts

All statesForest birds

Wood Thrush in Massachusetts has fallen sharply: down 62% on the route-weighted index since 1968.

-62%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 →
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 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 62% 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 83% by 2030 — from 4.7 in 2025 to a central estimate of 0.79 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±49.3%, with 100% of held-out values landing inside the 95% band.

-83%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 →
0.79Projected 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 →
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 →
±49.3%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 83% by 2030 — from 4.7 in 2025 to a central estimate of 0.79 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±49.3%, 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 →
20261.80.006.3
20271.50.006.1
20281.30.005.8
20291.00.005.6
20300.790.005.3

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
Belchertown1320251967
S Barre920251968
Monterey920252019
Warren 2920252010
Hancock920151997
N Orange820251968
Cummington 2820252015
N Oxford720241968
Maynard620251967
Warren620091968
Cheshire619941969
Chesterfield520251967
Sheffield420221969
Brockton320161967
Mansfield320251968
Chilmark219831969
Marion220251966
Wellfleet219961970
Newburyport220211967
E Dennis120041967
Prattville120181966
Littleton120251967

Wood Thrush Population Trend in Other States

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

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