BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Evening Grosbeak In Sierra Nevada

All regionsSierra NevadaGeneralists

Evening Grosbeak in Sierra Nevada has fallen sharply: down 64% on the route-weighted index since 1973.

-64%Since 1973TrendPercent 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 →
30Routes 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 →
53YearsYears 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 fallen sharply in Sierra Nevada: down 64% on the route-weighted index since 1973.

Forecast

If the recent trend holds, Evening Grosbeak in Sierra Nevada is projected to rise about 384% by 2029 — from 0.16 in 2024 to a central estimate of 0.77 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±212.7%, with 100% of held-out values landing inside the 95% band.

+384%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 →
0.77Projected 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 →
0.00–1.995% 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 →
±212.7%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 Sierra Nevada is projected to rise about 384% by 2029 — from 0.16 in 2024 to a central estimate of 0.77 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±212.7%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.810.002.0
20260.800.002.0
20270.790.002.0
20280.780.002.0
20290.770.001.9

Routes In Sierra Nevada

Routes recording Evening Grosbeak in Sierra Nevada.
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 →
GoumazCALIFORNIA102009
Eagle LakeCALIFORNIA62017
Bass LakeCALIFORNIA52008
Little TruckeeCALIFORNIA52023
SattleyCALIFORNIA32017
Butte MeadowCALIFORNIA32014
RivertonCALIFORNIA32016
LakeshoreCALIFORNIA32002
JohnsvilleCALIFORNIA22019
WoodfordsCALIFORNIA22023
LumberyardCALIFORNIA21989
Greenhorn MtCALIFORNIA21992
GeneseeCALIFORNIA22019
Hat CreekCALIFORNIA22017
Chaos CraterCALIFORNIA22018
Meadow ValleyCALIFORNIA22024
Pollock PinesCALIFORNIA22021
WawonaCALIFORNIA22014
Lassen ParkCALIFORNIA11989
WestvilleCALIFORNIA12022
Silver CityCALIFORNIA12010
Tuolumne GroveCALIFORNIA12010
Higgins CornCALIFORNIA11981
DownievilleCALIFORNIA12024
ChesterCALIFORNIA12016

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