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

Evening Grosbeak Population Trend in Washington

All statesGeneralists

Evening Grosbeak in Washington has fallen sharply: down 69% on the route-weighted index since 1970.

-69%Since 1970TrendPercent 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 →
75Routes 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 →
56YearsYears 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 WashingtonNotable 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 fallen sharply in Washington: down 69% on the route-weighted index since 1970.

Evening Grosbeak Population Forecast in Washington

If the recent trend holds, Evening Grosbeak in Washington is projected to rise about 14% by 2029 — from 1.9 in 2024 to a central estimate of 2.2 (95% range 0.00–9.0). A 5-year backtest shows a typical error of ±85.3%, with 100% of held-out values landing inside the 95% band.

+14%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 →
2.2Projected 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 →
0.00–9.095% 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 →
±85.3%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, Evening Grosbeak in Washington is projected to rise about 14% by 2029 — from 1.9 in 2024 to a central estimate of 2.2 (95% range 0.00–9.0). A 5-year backtest shows a typical error of ±85.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20252.50.009.3
20262.40.009.2
20272.40.009.1
20282.30.009.1
20292.20.009.0

Evening Grosbeak Survey Routes in Washington

Routes recording Evening Grosbeak in Washington.
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 →
Omak Creek2920221996
Winthrop2820091985
E. Mt. Adams2020241995
L. Wenatchee1520241993
Newhalem1420241968
Neilton1319751975
Raymond 2820242023
Mt Rainier820151991
Mendota 2720002000
Ronald720241973
Deer Park720011994
Cusick620241984
Carlton620131992
Nighthawk620131992
Mt. Adams620241993
Curlew520181993
Kendall420241981
Packwood420241976
Hurricane Rg420241992
Mt St Helens420242014
Greenwater420232015
Chewelah320191977
Ardenvoir319871969
Reardan319861972
Ellensburg320141981

Evening Grosbeak Population Trend in Other States

arizonacaliforniacoloradoconnecticutidahomainemassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonsouth-dakotautahvermontwisconsinwyoming

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