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Species · California · BBS 2025 Release · 1966–2024

Nuttall's Woodpecker Population Trend in California

All statesForest birds

Nuttall's Woodpecker in California has increased: up 49% on the route-weighted index since 1970.

+49%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 →
138Routes 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 Nuttall's Woodpecker Trends in CaliforniaNotable 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 Nuttall's Woodpecker in California. See the full index history below.

Nuttall's Woodpecker Population Forecast in California

If the recent trend holds, Nuttall's Woodpecker in California is projected to stay roughly flat through 2029, near 2.2 (95% range 1.6–2.8). A 5-year backtest shows a typical error of ±23.7%, with 80% of held-out values landing inside the 95% band.

-8%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 →
2.2Projected 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 →
1.6–2.895% 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 →
±23.7%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, Nuttall's Woodpecker in California is projected to stay roughly flat through 2029, near 2.2 (95% range 1.6–2.8). A 5-year backtest shows a typical error of ±23.7%, with 80% 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 →
20252.21.52.8
20262.21.62.8
20272.21.62.8
20282.21.62.8
20292.21.62.8

Nuttall's Woodpecker Survey Routes in California

Routes recording Nuttall's Woodpecker in 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 →
Coyote1720241972
Tres Pinos1620031968
Lake Berryessa1620242023
Rumsey1520081969
Folsom1320241984
Sisquoc1320141970
Moraga1320241972
Mt Laguna1219871970
Elizabeth Lk1220161970
Jackson1219921975
Yolla Bolly1220241973
White River1119921972
Tres Pinos 21120112005
Lake Cachuma1020161972
Oroville1020241972
Auburn919801969
Ono920121984
Lockwood920241972
Poloma920241993
Jofegan 2820242024
Elsinore Mtn820241970
Santa Ynez720191969
Gold Hill720241971
Zamora720241980
Carmel Val620241973

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