BirdAnalyst
Species · New Hampshire · BBS 2025 Release · 1966–2024

Evening Grosbeak Population Trend in New Hampshire

All statesGeneralists

Evening Grosbeak in New Hampshire has collapsed: down 79% on the route-weighted index since 1968.

-79%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 →
22Routes 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 →
51YearsYears 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 New HampshireNotable 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 New Hampshire: down 79% on the route-weighted index since 1968.

Evening Grosbeak Population Forecast in New Hampshire

If the recent trend holds, Evening Grosbeak in New Hampshire is projected to stay roughly flat through 2027, near 0.77 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±2183.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.77Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2.395% 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 →
±2183.2%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 New Hampshire is projected to stay roughly flat through 2027, near 0.77 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±2183.2%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.770.002.3
20240.770.002.3
20250.770.002.3
20260.770.002.3
20270.770.002.3

Evening Grosbeak Survey Routes in New Hampshire

Routes recording Evening Grosbeak in New Hampshire.
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 →
Stratford320141967
Peterborough220122000
Fitzwilliam220091970
Dover220012001
Hopkinton219981991
Epsom220071998
Strafford220051994
Gilmantn I W220101993
Wilmot220051978
Mt Chocorua220081967
Walpole220101990
Lempster220161989
Franconia220041968
Dixvil Notch219961977
Clarksville220071975
Concord120171991
Marlow120151987
Jefferson Hl120181966
Milan120121969
Glen120221979
East Kingston120062006
Jeffers Ntch120031993

Evening Grosbeak Population Trend in Other States

arizonacaliforniacoloradoconnecticutidahomainemassachusettsmichiganminnesotamontananevadanew-mexiconew-yorkoregonsouth-dakotautahvermontwashingtonwisconsinwyoming

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