BirdAnalyst
Species · BCR 32 · BBS 2026 Release · 1966–2025

Acorn Woodpecker In Coastal California

All regionsCoastal CaliforniaForest birds

Acorn Woodpecker in Coastal California has surged: up 95% on the route-weighted index since 1970.

+95%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 →
104Routes 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 surged in Coastal California: up 95% on the route-weighted index since 1970.

Acorn Woodpecker In Coastal California Population Forecast

If the recent trend holds, Acorn Woodpecker in Coastal California is projected to stay roughly flat through 2030, near 28 (95% range 21–35). A 5-year backtest shows a typical error of ±11.9%, with 100% of held-out values landing inside the 95% band.

-7%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 →
28Projected 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 →
21–3595% 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 →
±11.9%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 Coastal California is projected to stay roughly flat through 2030, near 28 (95% range 21–35). A 5-year backtest shows a typical error of ±11.9%, 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 →
2026272034
2027272034
2028282035
2029282135
2030282135

Routes In Coastal California

Routes recording Acorn Woodpecker in Coastal California.
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 →
Yolla BollyCALIFORNIA1322025
Mt LagunaCALIFORNIA1111987
LockwoodCALIFORNIA1062025
Lake BerryessaCALIFORNIA992025
Waterman GapCALIFORNIA902025
White RiverCALIFORNIA841992
Red BluffCALIFORNIA782025
Yokohl ValCALIFORNIA721997
AdelaidaCALIFORNIA722025
Carmel ValCALIFORNIA712025
FairfaxCALIFORNIA652024
CoalingaCALIFORNIA602022
Orange CoveCALIFORNIA602016
Cal Hot SpgsCALIFORNIA602019
ParkfieldCALIFORNIA582025
CoyoteCALIFORNIA562025
TehamaCALIFORNIA522022
Mesa GrandeCALIFORNIA512025
Lake HemetCALIFORNIA501986
SangerCALIFORNIA482024
Santa YnezCALIFORNIA472019
Cleveland Nf 2CALIFORNIA452022
OnoCALIFORNIA442012
Angelus OaksCALIFORNIA442017
S CatalinaCALIFORNIA432025

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