BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

Curve-billed Thrasher In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsArid-land birds

Curve-billed Thrasher in Sonoran and Mojave Deserts has edged up: up 18% on the route-weighted index since 1970.

+18%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 →
56YearsYears 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 70% by 2029 — from 2.0 in 2024 to a central estimate of 3.3 (95% range 0.79–5.9). A 5-year backtest shows a typical error of ±31.8%, with 100% of held-out values landing inside the 95% band.

+70%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 →
3.3Projected 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 →
0.79–5.995% 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 →
±31.8%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 Sonoran and Mojave Deserts is projected to rise about 70% by 2029 — from 2.0 in 2024 to a central estimate of 3.3 (95% range 0.79–5.9). A 5-year backtest shows a typical error of ±31.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.20.675.8
20263.30.705.8
20273.30.735.8
20283.30.765.9
20293.30.795.9

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 PrietARIZONA102024
Cutter 2ARIZONA102018
Cactus ForestARIZONA92024
WickenburgARIZONA82023
CoolidgeARIZONA71985
RivieraARIZONA52024
Alamo Res.ARIZONA52023
Casa GrandeARIZONA42023
QuartzsiteARIZONA32013
LagunaARIZONA31972
Red RockARIZONA32014
DatelandARIZONA22024
AjoARIZONA22008
Cibola LakeARIZONA22012
Ajo 2ARIZONA22022
Palo Verde 2ARIZONA22024
OatmanARIZONA12019

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