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Species · Maine · BBS 2025 Release · 1966–2024

Eastern Bluebird Population Trend in Maine

All statesForest birds

Eastern Bluebird in Maine has surged: up 199% on the route-weighted index since 1968.

+199%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 →
53Routes 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 MaineNotable 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 Maine: up 199% on the route-weighted index since 1968.

Eastern Bluebird Population Forecast in Maine

If the recent trend holds, Eastern Bluebird in Maine is projected to fall about 48% by 2029 — from 2.2 in 2024 to a central estimate of 1.1 (95% range 0.45–1.8). A 5-year backtest shows a typical error of ±47.1%, with 20% of held-out values landing inside the 95% band.

-48%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 →
1.1Projected 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 →
0.45–1.895% 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 →
±47.1%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, Eastern Bluebird in Maine is projected to fall about 48% by 2029 — from 2.2 in 2024 to a central estimate of 1.1 (95% range 0.45–1.8). A 5-year backtest shows a typical error of ±47.1%, with 20% 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 →
20251.10.381.8
20261.10.401.8
20271.10.411.8
20281.10.431.8
20291.10.451.8

Eastern Bluebird Survey Routes in Maine

Routes recording Eastern Bluebird in Maine.
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 →
Kittery Pt920242005
Turner919971972
Bowdoin Ctr620211991
Searsport620242002
Hancock520241992
Northfield 2520211993
Cape Neddick420241998
Westbrook420241985
Freedom420211973
Rome420231997
Harmony320241967
Eastbrook320241971
Reeds220241990
Otisfield Gr220141966
East Troy220191992
Warren219891975
Aurora220211990
Deblois219981983
Moose River220021998
Cambridge220141967
Medway219981998
Hudson219981975
Forest Sta219671967
Stacyville220222022
Cornville220242012

Eastern Bluebird Population Trend in Other States

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

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