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

Curve-billed Thrasher In Shortgrass Prairie

All regionsShortgrass PrairieArid-land birds

Curve-billed Thrasher in Shortgrass Prairie has increased: up 30% on the route-weighted index since 1970.

+30%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 →
58Routes 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 →
54YearsYears 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 →

No notable trend signals for Curve-billed Thrasher in Shortgrass Prairie. See the full index history below.

Curve-billed Thrasher In Shortgrass Prairie Population Forecast

If the recent trend holds, Curve-billed Thrasher in Shortgrass Prairie is projected to rise about 30% by 2029 — from 0.43 in 2024 to a central estimate of 0.56 (95% range 0.23–0.90). A 5-year backtest shows a typical error of ±71%, with 100% of held-out values landing inside the 95% band.

+30%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 →
0.56Projected 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 →
0.23–0.9095% 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 →
±71%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, Curve-billed Thrasher in Shortgrass Prairie is projected to rise about 30% by 2029 — from 0.43 in 2024 to a central estimate of 0.56 (95% range 0.23–0.90). A 5-year backtest shows a typical error of ±71%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.540.210.87
20260.550.210.88
20270.550.220.88
20280.560.230.89
20290.560.230.90

Routes In Shortgrass Prairie

Routes recording Curve-billed 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 →
SabinosoNEW-MEXICO62019
KermitTEXAS61994
MentoneTEXAS62015
PecosTEXAS62017
VariaderoNEW-MEXICO52022
GrenvilleNEW-MEXICO42021
ClovisNEW-MEXICO42024
RankinTEXAS42024
WinkTEXAS41986
VillegreenCOLORADO32024
FeltOKLAHOMA32024
CrowleyCOLORADO22024
UlyssesKANSAS22024
FarleyNEW-MEXICO22024
MaljamarNEW-MEXICO21975
PepNEW-MEXICO22015
LoganNEW-MEXICO22024
PlainsTEXAS22024
ChanningTEXAS22013
TexlineTEXAS22016
MidlandTEXAS22023
Mica ButteCOLORADO11981
GilpinCOLORADO12024
CampoCOLORADO12018
Cone MtnCOLORADO12024

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