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Species · Massachusetts · BBS 2026 Release · 1966–2025

Eastern Bluebird Population Trend in Massachusetts

All statesForest birds

Eastern Bluebird in Massachusetts has surged: up 551% on the route-weighted index since 1968.

+551%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 →
29Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eastern Bluebird 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 →

Eastern Bluebird has surged in Massachusetts: up 551% on the route-weighted index since 1968.

Eastern Bluebird Population Forecast in Massachusetts

If the recent trend holds, Eastern Bluebird in Massachusetts is projected to fall about 51% by 2030 — from 3.9 in 2025 to a central estimate of 1.9 (95% range 0.74–3.1). A 5-year backtest shows a typical error of ±60.8%, with 0% of held-out values landing inside the 95% band.

-51%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 →
1.9Projected 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 →
0.74–3.195% 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 →
±60.8%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, Eastern Bluebird in Massachusetts is projected to fall about 51% by 2030 — from 3.9 in 2025 to a central estimate of 1.9 (95% range 0.74–3.1). A 5-year backtest shows a typical error of ±60.8%, with 0% 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 →
20261.80.603.0
20271.80.643.0
20281.90.673.1
20291.90.713.1
20301.90.743.1

Eastern Bluebird Survey Routes in Massachusetts

Routes recording Eastern Bluebird 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 →
Belchertown1520251967
Maynard1120251988
Littleton820241967
Mansfield720251992
N Oxford620251995
S Barre520251972
Monterey520252019
Warren 2520252012
Chesterfield420241968
Cummington 2420252016
Ware River320221993
Wellfleet 2320242018
N Orange220251968
Holden220252007
E Dennis120162013
Marion120241996
Wellfleet119661966
Prattville120171995
Brockton120191999
Newburyport120212000
E Pepperell119821967
Warren120051968
Cummington120131968
Cheshire119921976
Pittsfield120091968

Eastern Bluebird Population Trend in Other States

alabamaarizonaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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