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

Dusky Grouse In Great Basin

All regionsGreat BasinGeneralists

Dusky Grouse in Great Basin has fallen sharply: down 67% on the route-weighted index since 1976.

-67%Since 1976TrendPercent 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 →
6Routes 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 →
31YearsYears 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 →

Dusky Grouse has fallen sharply in Great Basin: down 67% on the route-weighted index since 1976.

Dusky Grouse In Great Basin Population Forecast

If the recent trend holds, Dusky Grouse in Great Basin is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±92.4%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.0495% 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 →
±92.4%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, Dusky Grouse in Great Basin is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±92.4%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.010.000.04
20260.010.000.04
20270.000.000.04
20280.000.000.04
20290.000.000.04

Routes In Great Basin

Routes recording Dusky Grouse 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 →
JarbidgeNEVADA92014
BakerIDAHO32024
WinthropWASHINGTON32022
SquirrelIDAHO12008
AustinNEVADA12014
L. WenatcheeWASHINGTON12023

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