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

Bewick's Wren Population Trend in Arizona

All statesForest birds

Bewick's Wren in Arizona has fallen sharply: down 51% on the route-weighted index since 1970.

-51%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 →
64Routes 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 Bewick's Wren 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 →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Bewick's Wren has fallen sharply in Arizona: down 51% on the route-weighted index since 1970.

Bewick's Wren Population Forecast in Arizona

If the recent trend holds, Bewick's Wren in Arizona is projected to rise about 75% by 2029 — from 2.5 in 2024 to a central estimate of 4.3 (95% range 0.00–14). A 5-year backtest shows a typical error of ±189.3%, with 100% of held-out values landing inside the 95% band.

+75%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 →
4.3Projected 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 →
0.00–1495% 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 →
±189.3%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, Bewick's Wren in Arizona is projected to rise about 75% by 2029 — from 2.5 in 2024 to a central estimate of 4.3 (95% range 0.00–14). A 5-year backtest shows a typical error of ±189.3%, 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 →
20254.70.0014
20264.60.0014
20274.50.0014
20284.40.0014
20294.30.0014

Bewick's Wren Survey Routes in Arizona

Routes recording Bewick's Wren 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 →
Zeniff4419841969
Black Mesa3719951988
Wikieup3520191994
Dragoon2920091993
Patagonia1920241968
Rucker1820091993
Peña Blanca1720241975
Forest Lakes1420241993
Amado1320231993
Redington1020231993
Portal920241975
Pomerene920241968
House Rock820221969
Aztec Peak719781974
Cutter 2720182015
Sprucedale720221992
Mormon Lake619741968
Page620151993
Cutter620141992
Sunizona519921968
Sunizona 2520242001
Hunt420061969
Dateland420161990
Tonto Vill.420211992
Carr Mtn420241985

Bewick's Wren Population Trend in Other States

alabamaarkansascaliforniacoloradoidahoillinoisindianaiowakansaskentuckymarylandmississippimissourinevadanew-mexiconorth-carolinaohiooklahomaoregonpennsylvaniatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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