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Species · Colorado · BBS 2025 Release · 1966–2024

Gunnison Sage-Grouse Population Trend in Colorado

All statesGeneralists

Gunnison Sage-Grouse in Colorado has collapsed: down 77% on the route-weighted index since 1995.

-77%Since 1995TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
24YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Gunnison Sage-Grouse Trends in ColoradoNotable 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 →

Gunnison Sage-Grouse has collapsed in Colorado: down 77% on the route-weighted index since 1995.

Gunnison Sage-Grouse Population Forecast in Colorado

If the recent trend holds, Gunnison Sage-Grouse in Colorado is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±76.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.03Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1495% 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 →
±76.7%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, Gunnison Sage-Grouse in Colorado is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±76.7%, with 100% of held-out values landing inside the 95% band.19792028
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 →
20240.030.000.14
20250.030.000.14
20260.030.000.14
20270.030.000.14
20280.030.000.14

Gunnison Sage-Grouse Survey Routes in Colorado

Routes recording Gunnison Sage-Grouse in Colorado.
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 →
Basin720002000
Colona519791979
Powderhorn320231995
Doyleville120211994
Parlin120152015
Paonia119981998

Gunnison Sage-Grouse Population Trend in Other States

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