BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Greater Sage-Grouse

PhasianidaeGame birdsCentrocercus urophasianus

Greater Sage-Grouse has declined: down 27% on the route-weighted index since 1970.

-27%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 →
195RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Greater Sage-Grouse

The Greater Sage-Grouse (Centrocercus urophasianus) is a North American member of the Pheasants, Grouse & Turkeys (Phasianidae). In this analysis it is grouped with the game birds.

Size
12–47 in long (30–120 cm) — a ground-dwelling game bird (typical for the family)
Habitat
Fields, brushland, prairie and the forest floor, where it forages and nests on the ground.
Diet
Seeds, grain, buds, leaves and insects gathered on the ground.
Range
Recorded on 195 Breeding Bird Survey routes across 10 states, most concentrated in the Northern Rockies.
Family
Phasianidae · Game birds

Notable Greater Sage-Grouse TrendsNotable 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 Greater Sage-Grouse. See the full index history below.

Greater Sage-Grouse Population Forecast

If the recent trend holds, Greater Sage-Grouse is projected to fall about 49% by 2029 — from 0.08 in 2024 to a central estimate of 0.04 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±165.3%, with 100% of held-out values landing inside the 95% band.

-49%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 →
0.00–0.1095% 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 →
±165.3%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, Greater Sage-Grouse is projected to fall about 49% by 2029 — from 0.08 in 2024 to a central estimate of 0.04 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±165.3%, 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 →
20250.040.000.10
20260.040.000.10
20270.040.000.10
20280.040.000.10
20290.040.000.10

Where the Greater Sage-Grouse Is Detected

BBS routes recording Greater Sage-Grouse, sized by most recent count.

Greater Sage-Grouse Population Trend by State

Greater Sage-Grouse population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
California+397%19777
Colorado-84%197510
Idaho-43%197422
Montana-79%197123
Nevada-39%197017
North Dakotainsufficient datan/a1
Oregon-19%197514
South Dakotainsufficient datan/a1
Utah-92%197419
Wyoming-80%197081

Greater Sage-Grouse Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Greater Sage-Grouse population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Great Basin-53%197059
Northern Rockies-78%197067
Prairie Potholes+65%19833
Southern Rockies / Colorado Plateau-94%197421
Badlands and Prairies+34%197045

Greater Sage-Grouse Conservation Status

Our route-weighted index shows it down about 27% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.