BirdAnalyst
Species · BCR 35 · BBS 2025 Release · 1966–2024

Curve-billed Thrasher In Chihuahuan Desert

All regionsChihuahuan DesertArid-land birds

Curve-billed Thrasher in Chihuahuan Desert has edged down: down 15% on the route-weighted index since 1969.

-15%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 →
52Routes 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 →

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

Curve-billed Thrasher In Chihuahuan Desert Population Forecast

If the recent trend holds, Curve-billed Thrasher in Chihuahuan Desert is projected to fall about 27% by 2029 — from 1.6 in 2024 to a central estimate of 1.1 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±22%, with 100% of held-out values landing inside the 95% band.

-27%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 →
1.1Projected 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 →
0.00–2.695% 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 →
±22%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 Chihuahuan Desert is projected to fall about 27% by 2029 — from 1.6 in 2024 to a central estimate of 1.1 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±22%, 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 →
20251.20.002.7
20261.20.002.6
20271.20.002.6
20281.10.002.6
20291.10.002.6

Routes In Chihuahuan Desert

Routes recording Curve-billed Thrasher in Chihuahuan Desert.
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 →
PumpvilleTEXAS122024
ComstockTEXAS82017
GirvinTEXAS82024
CornudasTEXAS62018
Ft. DavisTEXAS62023
JornadaNEW-MEXICO52024
Van HornTEXAS42024
GageNEW-MEXICO32024
LakewoodNEW-MEXICO32019
Bitter LakeNEW-MEXICO32023
ValentineTEXAS31987
Casa PiedraTEXAS32022
LangtryTEXAS31997
Quitman Cyn.TEXAS32009
MarathonTEXAS32023
RoswellNEW-MEXICO22023
DemingNEW-MEXICO21971
Red RockNEW-MEXICO22024
QueenNEW-MEXICO22015
ColumbusNEW-MEXICO22024
Lake ValleyNEW-MEXICO22021
Devils R CynTEXAS22023
ToyahvaleTEXAS22024
CanutilloTEXAS22002
MarfaTEXAS22024

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