BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Bewick's Wren In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Bewick's Wren in Sierra Madre Occidental has fallen sharply: down 62% on the route-weighted index since 1970.

-62%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 →
36Routes 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 →

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 Sierra Madre Occidental: down 62% on the route-weighted index since 1970.

Bewick's Wren In Sierra Madre Occidental Population Forecast

If the recent trend holds, Bewick's Wren in Sierra Madre Occidental is projected to rise about 30% by 2029 — from 5.6 in 2024 to a central estimate of 7.3 (95% range 0.00–21). A 5-year backtest shows a typical error of ±133.5%, with 100% of held-out values landing inside the 95% band.

+30%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 →
7.3Projected 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 →
0.00–2195% 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 →
±133.5%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, Bewick's Wren in Sierra Madre Occidental is projected to rise about 30% by 2029 — from 5.6 in 2024 to a central estimate of 7.3 (95% range 0.00–21). A 5-year backtest shows a typical error of ±133.5%, 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 →
20258.20.0022
20267.90.0021
20277.70.0021
20287.50.0021
20297.30.0021

Routes In Sierra Madre Occidental

Routes recording Bewick's Wren in Sierra Madre Occidental.
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 →
DragoonARIZONA292009
PatagoniaARIZONA192024
RuckerARIZONA182009
Peña BlancaARIZONA172024
Forest LakesARIZONA142024
AmadoARIZONA132023
Emory PassNEW-MEXICO112024
RedingtonARIZONA102023
PomereneARIZONA92024
PortalARIZONA92024
Aztec PeakARIZONA71978
SprucedaleARIZONA72022
Mormon LakeARIZONA61974
CutterARIZONA62014
SunizonaARIZONA51992
Sunizona 2ARIZONA52024
Tonto Vill.ARIZONA42021
Carr MtnARIZONA42024
MagdalenaNEW-MEXICO42024
Skull ValleyARIZONA32024
ReserveNEW-MEXICO32019
Vicks PeakNEW-MEXICO32024
BlueARIZONA21990
Bartlett ResARIZONA22024
Happy JackARIZONA22013

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