BirdAnalyst
Species · BCR 21 · BBS 2026 Release · 1966–2025

Curve-billed Thrasher In Oaks and Prairies

All regionsOaks and PrairiesArid-land birds

Curve-billed Thrasher in Oaks and Prairies has collapsed: down 84% on the route-weighted index since 1970.

-84%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 →
11Routes 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 →
53YearsYears 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 →

Curve-billed Thrasher has collapsed in Oaks and Prairies: down 84% on the route-weighted index since 1970.

Curve-billed Thrasher In Oaks and Prairies Population Forecast

If the recent trend holds, Curve-billed Thrasher in Oaks and Prairies is projected to stay roughly flat through 2030, near 0.14 (95% range 0.00–0.54). A 5-year backtest shows a typical error of ±276.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.14Projected 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 →
0.00–0.5495% 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 →
±276.6%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, Curve-billed Thrasher in Oaks and Prairies is projected to stay roughly flat through 2030, near 0.14 (95% range 0.00–0.54). A 5-year backtest shows a typical error of ±276.6%, 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 →
20260.150.000.56
20270.150.000.55
20280.140.000.55
20290.140.000.55
20300.140.000.54

Routes In Oaks and Prairies

Routes recording Curve-billed Thrasher in Oaks and Prairies.
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 →
BriteTEXAS42021
MegargelTEXAS32022
Three RiversTEXAS22025
HobsonTEXAS12019
CampbelltonTEXAS12023
LockhartTEXAS12011
Lone OakTEXAS12011
OsageTEXAS12006
AlbanyTEXAS12019
OlneyTEXAS12003
Whit Mtn.TEXAS11995

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