BirdAnalyst
Species · Texas · BBS 2026 Release · 1966–2025

Curve-billed Thrasher Population Trend in Texas

All statesArid-land birds

Curve-billed Thrasher in Texas has fallen sharply: down 68% on the route-weighted index since 1969.

-68%Since 1969TrendPercent 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 →
129Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Curve-billed Thrasher Trends in TexasNotable 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 →

Curve-billed Thrasher has fallen sharply in Texas: down 68% on the route-weighted index since 1969.

Curve-billed Thrasher Population Forecast in Texas

If the recent trend holds, Curve-billed Thrasher in Texas is projected to fall about 38% by 2030 — from 0.81 in 2025 to a central estimate of 0.50 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±20.8%, with 100% of held-out values landing inside the 95% band.

-38%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 →
0.50Projected 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 →
0.00–1.395% 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 →
±20.8%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 Texas is projected to fall about 38% by 2030 — from 0.81 in 2025 to a central estimate of 0.50 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±20.8%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.570.001.4
20270.560.001.4
20280.540.001.3
20290.520.001.3
20300.500.001.3

Curve-billed Thrasher Survey Routes in Texas

Routes recording Curve-billed Thrasher in Texas.
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 →
Millett1420121995
Millett 21320242015
Pumpville1320252006
Encinal1220101969
Bear Mtn1120251988
Ft. Davis1120252004
Cavasara Cr.1020231996
Devils R Cyn920252012
Agua Nueva820231969
Weinert819941987
Comstock820171973
Girvin820241979
Encinal 2720252011
Catarina 3720252018
George West620251967
Hondo620251969
Cornudas620181968
Catarina 2620172011
Kermit619941994
Mentone620151999
Pecos620172017
Randado520251967
El Sauz520231993
Lag Atascosa420251969
Zapata419871967

Curve-billed Thrasher Population Trend in Other States

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