BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Evening Grosbeak In Great Basin

All regionsGreat BasinForest birds

Evening Grosbeak in Great Basin has collapsed: down 80% on the route-weighted index since 1970.

-80%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 →
77Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Great Basin: down 80% on the route-weighted index since 1970.

Evening Grosbeak In Great Basin Population Forecast

If the recent trend holds, Evening Grosbeak in Great Basin is projected to rise about 12% by 2030 — from 0.53 in 2025 to a central estimate of 0.60 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±145.9%, with 100% of held-out values landing inside the 95% band.

+12%Change by 2030TrendPercent 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 →
0.60Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–3.895% 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 →
±145.9%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 Great Basin is projected to rise about 12% by 2030 — from 0.53 in 2025 to a central estimate of 0.60 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±145.9%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.770.004.0
20270.730.004.0
20280.680.003.9
20290.640.003.9
20300.600.003.8

Routes In Great Basin

Routes recording Evening Grosbeak in Great Basin.
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 →
WinthropWASHINGTON282009
L. WenatcheeWASHINGTON212025
Barnes ValOREGON171987
DorrisCALIFORNIA142011
Harney LakeOREGON141996
Clear Lk ResCALIFORNIA131991
PauninaOREGON122012
RonaldWASHINGTON122025
E. Mt. AdamsWASHINGTON122025
Dell SpringOREGON111988
MacdoelCALIFORNIA61994
PendletonOREGON61994
Hardware RanchUTAH61994
SnowdenWASHINGTON62025
CarltonWASHINGTON62013
NighthawkWASHINGTON62013
ZumwaltOREGON51999
RimrockWASHINGTON52025
Blewett PassWASHINGTON52025
BlyOREGON41992
NewhalemWASHINGTON42025
KendallWASHINGTON42024
TionestaCALIFORNIA32021
Fall River MillsCALIFORNIA32007
Medicine Mtn.CALIFORNIA32021

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.