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

Bendire's Thrasher Population Trend in Arizona

All statesGeneralists

Bendire's Thrasher in Arizona has declined: down 36% on the route-weighted index since 1970.

-36%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 →
43Routes 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 Bendire's 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 Bendire's Thrasher in Arizona. See the full index history below.

Bendire's Thrasher Population Forecast in Arizona

If the recent trend holds, Bendire's Thrasher in Arizona is projected to fall about 50% by 2029 — from 0.26 in 2024 to a central estimate of 0.13 (95% range 0.00–0.61). A 5-year backtest shows a typical error of ±57.4%, with 100% of held-out values landing inside the 95% band.

-50%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 →
0.13Projected 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 →
0.00–0.6195% 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 →
±57.4%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, Bendire's Thrasher in Arizona is projected to fall about 50% by 2029 — from 0.26 in 2024 to a central estimate of 0.13 (95% range 0.00–0.61). A 5-year backtest shows a typical error of ±57.4%, 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 →
20250.170.000.65
20260.160.000.64
20270.150.000.63
20280.140.000.62
20290.130.000.61

Bendire's Thrasher Survey Routes in Arizona

Routes recording Bendire's 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 →
Wickenburg1120232019
Yampai519731970
Florence519761972
Cutter 2520182018
Mt Trumbull419801974
Zeniff319681968
New River320161974
San Simon320101975
Page320071993
Alamo Res.320242015
Palo Verde320111998
Cactus Forest320241991
Round Rock219891989
Squaw Peak219701968
Wikieup220241994
Coolidge219851974
Palo Verde 2220232017
Riviera220181993
Gila Bend220191995
Navajo Trail220171994
Clay Spring220141988
Carr Mtn220192019
Dragoon120012001
Oraibi119961996
Hunt120061968

Bendire's Thrasher Population Trend in Other States

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