BirdAnalyst
Species · Maine · BBS 2025 Release · 1966–2024

Rose-breasted Grosbeak Population Trend in Maine

All statesGeneralists

Rose-breasted Grosbeak in Maine has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
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 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 61% 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 fall about 28% by 2029 — from 1.2 in 2024 to a central estimate of 0.87 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±79.7%, with 100% of held-out values landing inside the 95% band.

-28%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 →
0.87Projected 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 →
0.00–4.795% 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 →
±79.7%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 fall about 28% by 2029 — from 1.2 in 2024 to a central estimate of 0.87 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±79.7%, 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 →
20251.10.004.9
20261.10.004.8
20270.990.004.8
20280.930.004.7
20290.870.004.7

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
Carrying Pl420241979
Ludlow419981968
Priestly Br.420131994
Baker Lake 2420132010
Jefferson420091991
Hermon320191966
Searsport320242002
Cape Neddick220221974
Biddeford220061973
Hartford220241975
East Troy220181973
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 2026-05-22.