BirdAnalyst
Species · Washington · BBS 2025 Release · 1966–2024

Ruffed Grouse Population Trend in Washington

All statesGeneralists

Ruffed Grouse in Washington has fallen sharply: down 64% on the route-weighted index since 1970.

-64%Since 1970TrendPercent 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 →
44Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ruffed 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 →

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 →

Ruffed Grouse has fallen sharply in Washington: down 64% on the route-weighted index since 1970.

Ruffed Grouse Population Forecast in Washington

If the recent trend holds, Ruffed Grouse in Washington is projected to fall about 66% by 2029 — from 0.10 in 2024 to a central estimate of 0.04 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±71.5%, with 100% of held-out values landing inside the 95% band.

-66%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 →
0.04Projected 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 →
0.00–0.2095% 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 →
±71.5%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, Ruffed Grouse in Washington is projected to fall about 66% by 2029 — from 0.10 in 2024 to a central estimate of 0.04 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±71.5%, with 100% 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 →
20250.040.000.21
20260.040.000.21
20270.040.000.21
20280.040.000.20
20290.040.000.20

Ruffed Grouse Survey Routes in Washington

Routes recording Ruffed 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 →
Omak Creek420211996
Taholah319941994
Cusick320241982
Asotin219831983
Sullivan Lake 2220232004
Bickleton219841984
Cedar Falls220141992
Deer Park220091999
Ozette120012001
Newhalem120171973
Twisp120051971
Montesand120101989
Keller120061972
Chewelah119991981
Kamilche119761968
L Pend O Nwr120211998
E. Mt. Adams120182003
Reardan119711971
Bunker Hill119891989
Cougar120212021
Rimrock119861969
Snowden120152005
Kendall120061981
Winthrop120191983
Tonasket120021982

Ruffed Grouse Population Trend in Other States

alaskaarkansascaliforniaconnecticutgeorgiaidahoindianaiowakentuckymainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawest-virginiawisconsinwyoming

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