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

Sage Thrasher In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGeneralists

Sage Thrasher in Southern Rockies / Colorado Plateau has surged: up 151% on the route-weighted index since 1970.

+151%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 →
141Routes 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 →
56YearsYears 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 increasecomputed 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 →

Sage Thrasher has surged in Southern Rockies / Colorado Plateau: up 151% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Sage Thrasher in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 3.1 (95% range 1.4–4.7). A 5-year backtest shows a typical error of ±18.1%, with 100% of held-out values landing inside the 95% band.

-2%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 →
3.1Projected 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 →
1.4–4.795% 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 →
±18.1%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, Sage Thrasher in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 3.1 (95% range 1.4–4.7). A 5-year backtest shows a typical error of ±18.1%, 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 →
20253.01.44.6
20263.01.44.6
20273.01.44.7
20283.01.44.7
20293.11.44.7

Routes In Southern Rockies / Colorado Plateau

Routes recording Sage Thrasher 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 →
WaldenCOLORADO622024
DinosaurCOLORADO482024
AltonahUTAH372015
PowderhornCOLORADO322023
AntonitoCOLORADO282004
BlancaCOLORADO241987
M Warner ResUTAH232024
BasinCOLORADO222024
San LuisCOLORADO202024
MoscaCOLORADO192024
MesitaCOLORADO192024
JensenUTAH192024
Wilson CreekCOLORADO182024
VernalUTAH172018
Bullfrog BayUTAH172008
MoffatCOLORADO132024
DoylevilleCOLORADO132024
Cochetopa PassCOLORADO132024
Willow CreekUTAH132024
GreasewoodARIZONA121996
Yellowjacket PassCOLORADO112024
WestcliffeCOLORADO102015
Moon Lake 2UTAH102023
YampaCOLORADO92023
AlamosaCOLORADO92024

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