BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Blue Grosbeak In Great Basin

All regionsGreat BasinGeneralists

Blue Grosbeak in Great Basin has declined: down 43% on the route-weighted index since 1971.

-43%Since 1971TrendPercent 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 →
13Routes 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 →
45YearsYears 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 →

No notable trend signals for Blue Grosbeak in Great Basin. See the full index history below.

Forecast

If the recent trend holds, Blue Grosbeak in Great Basin is projected to fall about 92% by 2029 — from 0.11 in 2024 to a central estimate of 0.01 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±81.6%, with 80% of held-out values landing inside the 95% band.

-92%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 →
0.01Projected 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 →
0.00–0.0795% 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 →
±81.6%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, Blue Grosbeak in Great Basin is projected to fall about 92% by 2029 — from 0.11 in 2024 to a central estimate of 0.01 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±81.6%, with 80% 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 →
20250.010.000.07
20260.010.000.07
20270.010.000.07
20280.010.000.07
20290.010.000.07

Routes In Great Basin

Routes recording Blue 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 →
Meadow VallyNEVADA92024
Oak CityUTAH42024
GoshenUTAH32024
Iron SpringsUTAH22001
Daniels ResIDAHO11997
PrestonIDAHO11992
MidasNEVADA11994
HikoNEVADA12016
Chimney Res.NEVADA12023
FallonNEVADA12004
AustinNEVADA12015
Timpie SpgUTAH11983
NewcastleUTAH12009

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