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Species · Arizona · BBS 2025 Release · 1966–2024

Lewis's Woodpecker Population Trend in Arizona

All statesForest birds

Lewis's Woodpecker in Arizona has collapsed: down 94% on the route-weighted index since 1970.

-94%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 →
11Routes 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 →
23YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lewis's Woodpecker Trends in ArizonaNotable 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 →

Lewis's Woodpecker has collapsed in Arizona: down 94% on the route-weighted index since 1970.

Lewis's Woodpecker Population Forecast in Arizona

If the recent trend holds, Lewis's Woodpecker in Arizona is projected to stay roughly flat through 2015, near 0.00 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±355.9%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.4095% 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 →
±355.9%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, Lewis's Woodpecker in Arizona is projected to stay roughly flat through 2015, near 0.00 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±355.9%, with 100% of held-out values landing inside the 95% band.19682015
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 →
20110.000.000.40
20120.000.000.40
20130.000.000.40
20140.000.000.40
20150.000.000.40

Lewis's Woodpecker Survey Routes in Arizona

Routes recording Lewis's Woodpecker in Arizona.
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 →
Mormon Lake519741968
Tsaile219931993
Greasewood219961996
House Rock120042004
Round Rock119761968
Flagstaff120101990
Alpine120021997
Sawmill120101988
Sprucedale119931993
Blue119881988
Maine120062006

Lewis's Woodpecker Population Trend in Other States

californiacoloradoidahomontananebraskanevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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