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Species · BCR 18 · BBS 2025 Release · 1966–2024

Sage Thrasher In Shortgrass Prairie

All regionsShortgrass PrairieGeneralists

Sage Thrasher in Shortgrass Prairie has fallen sharply: down 74% on the route-weighted index since 1982.

-74%Since 1982TrendPercent 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 →
16Routes 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 →
21YearsYears 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 →

Sage Thrasher has fallen sharply in Shortgrass Prairie: down 74% on the route-weighted index since 1982.

Sage Thrasher In Shortgrass Prairie Population Forecast

If the recent trend holds, Sage Thrasher in Shortgrass Prairie is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±92.6%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.0395% 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 →
±92.6%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 Shortgrass Prairie is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±92.6%, with 80% 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 →
20250.010.000.04
20260.010.000.04
20270.000.000.04
20280.000.000.04
20290.000.000.03

Routes In Shortgrass Prairie

Routes recording Sage Thrasher in Shortgrass Prairie.
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 →
AbarrCOLORADO21969
Mica ButteCOLORADO21982
CrowleyCOLORADO22017
HaswellCOLORADO22006
GilpinCOLORADO12017
EdisonCOLORADO12021
VillegreenCOLORADO12004
Kiowa 2COLORADO12024
NunnCOLORADO12014
EllicottCOLORADO12024
TimpasCOLORADO12015
RockportCOLORADO12016
Arsenal 2COLORADO12022
Murray LakeNEBRASKA12015
FarleyNEW-MEXICO12011
CheyenneWYOMING11995

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