BirdAnalyst
Species · Arizona · BBS 2025 Release · 1966–2024

Curve-billed Thrasher Population Trend in Arizona

All statesArid-land birds

Curve-billed Thrasher in Arizona has increased: up 29% on the route-weighted index since 1970.

+29%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 →
54Routes 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 →
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 Curve-billed Thrasher Trends in ArizonaNotable 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 Arizona. See the full index history below.

Curve-billed Thrasher Population Forecast in Arizona

If the recent trend holds, Curve-billed Thrasher in Arizona is projected to rise about 31% by 2029 — from 2.9 in 2024 to a central estimate of 3.8 (95% range 1.1–6.4). A 5-year backtest shows a typical error of ±29%, with 100% of held-out values landing inside the 95% band.

+31%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 →
3.8Projected 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 →
1.1–6.495% 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 →
±29%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 Arizona is projected to rise about 31% by 2029 — from 2.9 in 2024 to a central estimate of 3.8 (95% range 1.1–6.4). A 5-year backtest shows a typical error of ±29%, 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 →
20253.71.16.4
20263.71.16.4
20273.71.16.4
20283.81.16.4
20293.81.16.4

Curve-billed Thrasher Survey Routes in Arizona

Routes recording Curve-billed Thrasher in Arizona.
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 River4820161974
Organ Pipe2920231990
Red Rock 22020242015
Florence1919881968
Lukeville1719811975
Bates Well1620231995
Cutter1620141992
Bartlett Res1420241992
Pisinimo1119931992
Wikieup1020241992
Cutter 21020182015
Cabeza Priet1020241993
Sunizona919971968
Cactus Forest920241991
Wickenburg820232017
Coolidge719851974
Patagonia720241968
Carr Mtn720241985
Dragoon620091993
Pomerene620231969
Sahuarita620241992
Riviera520241992
Alamo Res.520231992
Redington520231993
Amado520231994

Curve-billed Thrasher Population Trend in Other States

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