BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Dusky Grouse In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGeneralists

Dusky Grouse in Southern Rockies / Colorado Plateau has fallen sharply: down 68% on the route-weighted index since 1975.

-68%Since 1975TrendPercent 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 →
56Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
38YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Dusky Grouse has fallen sharply in Southern Rockies / Colorado Plateau: down 68% on the route-weighted index since 1975.

Dusky Grouse In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Dusky Grouse in Southern Rockies / Colorado Plateau is projected to fall about 44% by 2029 — from 0.05 in 2024 to a central estimate of 0.03 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±86.3%, with 100% of held-out values landing inside the 95% band.

-44%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 →
0.03Projected 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 →
0.00–0.0995% 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 →
±86.3%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 Southern Rockies / Colorado Plateau is projected to fall about 44% by 2029 — from 0.05 in 2024 to a central estimate of 0.03 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±86.3%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.030.000.09
20260.030.000.09
20270.030.000.09
20280.030.000.09
20290.030.000.09

Routes In Southern Rockies / Colorado Plateau

Routes recording Dusky Grouse in Southern Rockies / Colorado Plateau.
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 →
Pagosa SpgsCOLORADO51975
RadiumCOLORADO41998
Colona 2COLORADO22021
Blackhead PkCOLORADO22021
Dunckley PasCOLORADO22024
Yellowjacket PassCOLORADO22018
VallecitosNEW-MEXICO21999
Dry ParkARIZONA12010
YampaCOLORADO12007
Douglas PassCOLORADO12024
AspenCOLORADO11998
Cheesman LkCOLORADO12015
DeltaCOLORADO11976
ColonaCOLORADO12007
WaldenCOLORADO12008
Lost LakeCOLORADO12015
Willow PeakCOLORADO12016
UncompahgreCOLORADO12023
CastletonCOLORADO12013
GuffeyCOLORADO12006
Dolores RivCOLORADO12015
SummitvilleCOLORADO12024
Buffalo ParkCOLORADO11994
Deadman Rd.COLORADO12006
FlattopsCOLORADO12012

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