BirdAnalyst
Species · BCR 34 · BBS 2026 Release · 1966–2025

Acorn Woodpecker In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Acorn Woodpecker in Sierra Madre Occidental has risen sharply: up 72% on the route-weighted index since 1970.

+72%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 →
27Routes 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 →
57YearsYears 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 increasecomputed 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 →

Acorn Woodpecker has risen sharply in Sierra Madre Occidental: up 72% on the route-weighted index since 1970.

Acorn Woodpecker In Sierra Madre Occidental Population Forecast

If the recent trend holds, Acorn Woodpecker in Sierra Madre Occidental is projected to fall about 41% by 2030 — from 9.9 in 2025 to a central estimate of 5.9 (95% range 0.20–12). A 5-year backtest shows a typical error of ±18.9%, with 100% of held-out values landing inside the 95% band.

-41%Change by 2030TrendPercent 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 →
5.9Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.20–1295% 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 →
±18.9%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, Acorn Woodpecker in Sierra Madre Occidental is projected to fall about 41% by 2030 — from 9.9 in 2025 to a central estimate of 5.9 (95% range 0.20–12). A 5-year backtest shows a typical error of ±18.9%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20265.90.2312
20275.90.2212
20285.90.2112
20295.90.2112
20305.90.2012

Routes In Sierra Madre Occidental

Routes recording Acorn Woodpecker 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 →
Tonto Vill.ARIZONA702025
PortalARIZONA362025
PatagoniaARIZONA262025
Emory PassNEW-MEXICO262025
SprucedaleARIZONA182025
ReserveNEW-MEXICO162025
WilliamsARIZONA152025
AlpineARIZONA132025
Happy JackARIZONA132025
Mt. GrahamARIZONA92025
Mormon LakeARIZONA81974
PinetopARIZONA82022
PrescottARIZONA72025
Peña BlancaARIZONA62025
Skull Valley 2ARIZONA62025
SunizonaARIZONA41997
Carr MtnARIZONA32025
RuckerARIZONA32009
Aztec PeakARIZONA21978
Forest LakesARIZONA22025
Sunizona 2ARIZONA22025
Vicks PeakNEW-MEXICO22024
FlagstaffARIZONA12016
BlueARIZONA11990
PomereneARIZONA11980

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.