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

Spruce Grouse Population Trend in Alaska

All statesGeneralists

Spruce Grouse in Alaska has collapsed: down 83% on the route-weighted index since 1988.

-83%Since 1988TrendPercent 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 →
19Routes 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 →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Spruce Grouse Trends in AlaskaNotable 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 →

Spruce Grouse has collapsed in Alaska: down 83% on the route-weighted index since 1988.

Spruce Grouse Population Forecast in Alaska

If the recent trend holds, Spruce Grouse in Alaska is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±260.5%, 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 →
0.00–0.1095% 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 →
±260.5%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, Spruce Grouse in Alaska is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±260.5%, with 100% of held-out values landing inside the 95% band.19772029
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 →
20250.000.000.10
20260.000.000.10
20270.000.000.10
20280.000.000.10
20290.000.000.10

Spruce Grouse Survey Routes in Alaska

Routes recording Spruce Grouse in Alaska.
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 →
Tatalina220121997
Circle119961986
Mccarthy Rd2120242017
Monahan120132013
Chena Hot Spring 2120232023
Beaver Creek119771977
Whale Pass120172017
Willow120002000
Mcgrath119981998
Zarembo120241994
Ft. Richrdsn120081996
Dillingham120002000
Petersville119861986
Katmai N.P.120192019
Seven Lakes120221995
King Salmon120181997
Lake Louise120032003
Thorne Bay 2120182018
Savage120162016

Spruce Grouse Population Trend in Other States

idahomainemichiganminnesotamontananew-yorkwashington

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