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

Evening Grosbeak Population Trend in Maine

All statesGeneralists

Evening Grosbeak in Maine has collapsed: down 86% on the route-weighted index since 1968.

-86%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 →
67Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Evening 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 →

Evening Grosbeak has collapsed in Maine: down 86% on the route-weighted index since 1968.

Evening Grosbeak Population Forecast in Maine

If the recent trend holds, Evening Grosbeak in Maine is projected to fall about 83% by 2017 — from 0.08 in 2012 to a central estimate of 0.01 (95% range 0.00–11). A 5-year backtest shows a typical error of ±708.5%, with 100% of held-out values landing inside the 95% band.

-83%Change by 2017TrendPercent 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 →
0.01Projected 2017 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1195% 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 →
±708.5%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, Evening Grosbeak in Maine is projected to fall about 83% by 2017 — from 0.08 in 2012 to a central estimate of 0.01 (95% range 0.00–11). A 5-year backtest shows a typical error of ±708.5%, with 100% of held-out values landing inside the 95% band.19662017
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 →
20130.640.0012
20140.480.0011
20150.330.0011
20160.170.0011
20170.010.0011

Evening Grosbeak Survey Routes in Maine

Routes recording Evening 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 →
Northfield1419811976
Waite1019771977
Forest Sta920001966
Baxter819841977
Ludlow619981968
Boundary619971993
Greenville519991976
Grnd Lk Strm520001991
Cooper420031976
Moose River420081983
Big Twenty420081993
Telos420011995
Westbrook319931989
Wilson Mills320071983
South Arm319851979
Eastbrook319961979
Winn319991969
Hudson320001976
Clayton Lake320011977
Church Hill320051994
Newcastle220071990
Reeds220081995
Topsfield219791978
Hancock220001972
Castine220041986

Evening Grosbeak Population Trend in Other States

arizonacaliforniacoloradoconnecticutidahomassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonsouth-dakotautahvermontwashingtonwisconsinwyoming

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