BirdAnalyst
Species · Washington · BBS 2026 Release · 1966–2025

Dusky Grouse Population Trend in Washington

All statesGame birds

Dusky Grouse in Washington has declined: down 49% on the route-weighted index since 1992.

-49%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 →
10Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Dusky Grouse Trends in WashingtonNotable 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 Dusky Grouse in Washington. See the full index history below.

Dusky Grouse Population Forecast in Washington

If the recent trend holds, Dusky Grouse in Washington is projected to stay roughly flat through 2030, near 0.02 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±38.3%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.0895% 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 →
±38.3%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 Washington is projected to stay roughly flat through 2030, near 0.02 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±38.3%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.020.000.09
20270.020.000.09
20280.020.000.09
20290.020.000.08
20300.020.000.08

Dusky Grouse Survey Routes in Washington

Routes recording Dusky Grouse in Washington.
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 →
Winthrop320222018
Cloverland220251996
Omak Creek120221996
Keller120041971
Northport120071998
L. Wenatchee120232023
L Pend O Nwr120112011
Curlew120062004
Sullivan Lake 2120152015
Twin Lakes120182015

Dusky Grouse Population Trend in Other States

arizonacoloradoidahomontananevadanew-mexicooregonutahwyoming

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