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Species · Maine · BBS 2026 Release · 1966–2025

Rose-breasted Grosbeak Population Trend in Maine

All statesForest birds

Rose-breasted Grosbeak in Maine has fallen sharply: down 69% on the route-weighted index since 1968.

-69%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 →
76Routes 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 Rose-breasted Grosbeak 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 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 →

Rose-breasted Grosbeak has fallen sharply in Maine: down 69% on the route-weighted index since 1968.

Rose-breasted Grosbeak Population Forecast in Maine

If the recent trend holds, Rose-breasted Grosbeak in Maine is projected to rise about 40% by 2030 — from 0.56 in 2025 to a central estimate of 0.78 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±66.3%, with 100% of held-out values landing inside the 95% band.

+40%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 →
0.78Projected 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 →
0.00–4.595% 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 →
±66.3%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, Rose-breasted Grosbeak in Maine is projected to rise about 40% by 2030 — from 0.56 in 2025 to a central estimate of 0.78 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±66.3%, 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 →
20261.00.004.8
20270.960.004.7
20280.900.004.7
20290.840.004.6
20300.780.004.5

Rose-breasted Grosbeak Survey Routes in Maine

Routes recording Rose-breasted Grosbeak 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 →
Northfield2919811976
Waite1219771977
Benton719801977
Pillsbury Pd719681968
Washburn720051979
Clayton Lake 2720132010
Westbrook620241977
Turner620021973
Manchester619951971
Baxter619881977
Warren519901973
Ft Fairfield520051993
Otisfield Gr420151977
Ludlow419981968
Priestly Br.420131994
Baker Lake 2420132010
Jefferson420091991
East Troy320211973
Harmony320251967
Brooks320211977
Searsport320252002
Cape Neddick220221974
Biddeford220061973
Hartford220241975
Freedom220221973

Rose-breasted Grosbeak Population Trend in Other States

arkansasconnecticutgeorgiaillinoisindianaiowakansaskentuckymarylandmassachusettsmichiganminnesotamissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotatennesseevermontvirginiawest-virginiawisconsinwyoming

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