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

Evening Grosbeak Population Trend in Utah

All statesGeneralists

Evening Grosbeak in Utah has collapsed: down 94% on the route-weighted index since 1986.

-94%Since 1986TrendPercent 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 →
14Routes 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 →
32YearsYears 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 UtahNotable 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 Utah: down 94% on the route-weighted index since 1986.

Evening Grosbeak Population Forecast in Utah

If the recent trend holds, Evening Grosbeak in Utah is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±602%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.00Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2895% 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 →
±602%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 Utah is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±602%, with 100% of held-out values landing inside the 95% band.19702028
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 →
20240.000.000.28
20250.000.000.28
20260.000.000.28
20270.000.000.28
20280.000.000.28

Evening Grosbeak Survey Routes in Utah

Routes recording Evening Grosbeak in Utah.
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 →
Main Canyon720021999
Uintah Nf619941994
Hardware Ranch619941994
Alton419981998
Skyline Driv219961992
Grizzly Rdge220231994
Wasatch Nf220161993
Heber Mtn.220161996
Navajo Lake220221970
Timpie Spg119951995
Gooseberry119961996
Lost Cr. Res119971995
Beaver120031973
Soapstone120221996

Evening Grosbeak Population Trend in Other States

arizonacaliforniacoloradoconnecticutidahomainemassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonsouth-dakotavermontwashingtonwisconsinwyoming

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