BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

Blue Grosbeak In Northern Rockies

All regionsNorthern RockiesForest birds

Blue Grosbeak in Northern Rockies has surged: up 336% on the route-weighted index since 1992.

+336%Since 1992TrendPercent 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 →
12Routes 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 →
20YearsYears 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 Northern Rockies. See the full index history below.

Blue Grosbeak In Northern Rockies Population Forecast

If the recent trend holds, Blue Grosbeak in Northern Rockies is projected to fall about 31% by 2030 — from 0.07 in 2025 to a central estimate of 0.04 (95% range 0.02–0.07). A 5-year backtest shows a typical error of ±77.6%, with 40% of held-out values landing inside the 95% band.

-31%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 →
0.04Projected 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 →
0.02–0.0795% 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 →
±77.6%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 Northern Rockies is projected to fall about 31% by 2030 — from 0.07 in 2025 to a central estimate of 0.04 (95% range 0.02–0.07). A 5-year backtest shows a typical error of ±77.6%, with 40% of held-out values landing inside the 95% band.19872030
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 →
20260.040.010.07
20270.040.010.07
20280.040.010.07
20290.040.020.07
20300.040.020.07

Routes In Northern Rockies

Routes recording Blue Grosbeak in Northern Rockies.
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 →
EtheteWYOMING42025
MidvaleWYOMING32017
BasinWYOMING22025
GeboWYOMING22015
MaybellCOLORADO12017
Browns ParkCOLORADO12025
LayCOLORADO12022
LaurelMONTANA12022
GlenMONTANA12025
OttoWYOMING12025
TensleepWYOMING12025
Mtn ViewWYOMING12023

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