BirdAnalyst
Species · BCR 33 · BBS 2026 Release · 1966–2025

Curve-billed Thrasher In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsArid-land birds

Curve-billed Thrasher in Sonoran and Mojave Deserts has held roughly steady: down 8% on the route-weighted index since 1970.

-8%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 →
30Routes 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 Sonoran and Mojave Deserts. See the full index history below.

Curve-billed Thrasher In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Curve-billed Thrasher in Sonoran and Mojave Deserts is projected to rise about 344% by 2030 — from 0.71 in 2025 to a central estimate of 3.2 (95% range 0.56–5.8). A 5-year backtest shows a typical error of ±103.5%, with 80% of held-out values landing inside the 95% band.

+344%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 →
3.2Projected 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 →
0.56–5.895% 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 →
±103.5%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 Sonoran and Mojave Deserts is projected to rise about 344% by 2030 — from 0.71 in 2025 to a central estimate of 3.2 (95% range 0.56–5.8). A 5-year backtest shows a typical error of ±103.5%, with 80% 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 →
20263.10.465.7
20273.10.485.7
20283.10.515.7
20293.10.535.8
20303.20.565.8

Routes In Sonoran and Mojave Deserts

Routes recording Curve-billed Thrasher in Sonoran and Mojave Deserts.
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 →
New RiverARIZONA482016
Organ PipeARIZONA292023
Red Rock 2ARIZONA202024
FlorenceARIZONA191988
LukevilleARIZONA171981
Bates WellARIZONA162023
PisinimoARIZONA111993
WikieupARIZONA102024
Cabeza PrietARIZONA102025
Cutter 2ARIZONA102018
WickenburgARIZONA82023
CoolidgeARIZONA71985
RivieraARIZONA52025
Alamo Res.ARIZONA52023
Casa GrandeARIZONA42023
QuartzsiteARIZONA32013
LagunaARIZONA31972
Red RockARIZONA32014
Cactus ForestARIZONA32025
OatmanARIZONA22025
DatelandARIZONA22024
AjoARIZONA22008
Cibola LakeARIZONA22012
Ajo 2ARIZONA22022
Palo Verde 2ARIZONA22024

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