BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Sage Thrasher In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauArid-land birds

Sage Thrasher in Southern Rockies / Colorado Plateau has surged: up 139% on the route-weighted index since 1970.

+139%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 →
143Routes 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 →
57YearsYears 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 138% on the route-weighted index since 1970.

Sage Thrasher In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Sage Thrasher in Southern Rockies / Colorado Plateau is projected to rise about 13% by 2030 — from 2.7 in 2025 to a central estimate of 3.1 (95% range 1.4–4.7). A 5-year backtest shows a typical error of ±15.1%, with 100% of held-out values landing inside the 95% band.

+13%Change by 2030TrendPercent 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 2030 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 →
±15.1%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 rise about 13% by 2030 — from 2.7 in 2025 to a central estimate of 3.1 (95% range 1.4–4.7). A 5-year backtest shows a typical error of ±15.1%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.01.44.6
20273.01.44.6
20283.01.44.6
20293.01.44.7
20303.11.44.7

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 →
JensenUTAH322025
BicknellUTAH322025
DinosaurCOLORADO312025
BasinCOLORADO302025
WaldenCOLORADO292025
AntonitoCOLORADO282004
BlancaCOLORADO241987
PowderhornCOLORADO212025
San LuisCOLORADO202024
MoffatCOLORADO182025
MoscaCOLORADO182025
VernalUTAH172018
Bullfrog BayUTAH172008
DoylevilleCOLORADO162025
PaoniaCOLORADO162025
AltonahUTAH152025
M Warner ResUTAH152025
AlamosaCOLORADO132025
Willow CreekUTAH132024
GreasewoodARIZONA121996
Canyon RimsUTAH122025
DulceNEW-MEXICO112025
MonticelloUTAH112025
WestcliffeCOLORADO102015
Moon Lake 2UTAH102023

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.