BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Lewis's Woodpecker In Sierra Nevada

All regionsSierra NevadaForest birds

Lewis's Woodpecker in Sierra Nevada has collapsed: down 86% on the route-weighted index since 1972.

-86%Since 1972TrendPercent 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 →
9Routes 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 →
28YearsYears 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 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 Sierra Nevada: down 86% on the route-weighted index since 1972.

Lewis's Woodpecker In Sierra Nevada Population Forecast

If the recent trend holds, Lewis's Woodpecker in Sierra Nevada is projected to fall about 100% by 2029 — from 0.05 in 2024 to a central estimate of 0.00 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±127.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.2395% 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 →
±127.1%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 Sierra Nevada is projected to fall about 100% by 2029 — from 0.05 in 2024 to a central estimate of 0.00 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±127.1%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.020.000.24
20260.010.000.24
20270.010.000.23
20280.000.000.23
20290.000.000.23

Routes In Sierra Nevada

Routes recording Lewis's Woodpecker in Sierra Nevada.
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 →
Last ChanceCALIFORNIA82000
Eagle LakeCALIFORNIA21997
GeneseeCALIFORNIA12024
DownievilleCALIFORNIA11975
RivertonCALIFORNIA11978
Hat CreekCALIFORNIA12018
PaxtonCALIFORNIA12021
PlacervilleCALIFORNIA12004
WawonaCALIFORNIA12004

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