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Species · California · BBS 2025 Release · 1966–2024

Gila Woodpecker Population Trend in California

All statesArid-land birds

Gila Woodpecker in California has surged: up 144% on the route-weighted index since 1977.

+144%Since 1977TrendPercent 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 →
3Routes 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 →
20YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Gila 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 →

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 →

Gila Woodpecker has surged in California: up 144% on the route-weighted index since 1977.

Gila Woodpecker Population Forecast in California

If the recent trend holds, Gila Woodpecker in California is projected to fall about 28% by 2015 — from 0.09 in 2010 to a central estimate of 0.07 (95% range 0.02–0.11). A 5-year backtest shows a typical error of ±119%, with 40% of held-out values landing inside the 95% band.

-28%Change by 2015TrendPercent 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 →
0.07Projected 2015 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.02–0.1195% 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 →
±119%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, Gila Woodpecker in California is projected to fall about 28% by 2015 — from 0.09 in 2010 to a central estimate of 0.07 (95% range 0.02–0.11). A 5-year backtest shows a typical error of ±119%, with 40% of held-out values landing inside the 95% band.19732015
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 →
20110.060.010.11
20120.060.010.11
20130.060.010.11
20140.060.010.11
20150.070.020.11

Gila Woodpecker Survey Routes in California

Routes recording Gila 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 →
Imperial Dam1020101973
Alamo River219821982
Palo Verde120092009

Gila Woodpecker Population Trend in Other States

arizonanew-mexico

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