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

Hairy Woodpecker In Sierra Nevada

All regionsSierra NevadaForest birds

Hairy Woodpecker in Sierra Nevada has surged: up 83% on the route-weighted index since 1970.

+83%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 →
40Routes 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 →
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 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 →

Hairy Woodpecker has surged in Sierra Nevada: up 83% on the route-weighted index since 1970.

Hairy Woodpecker In Sierra Nevada Population Forecast

If the recent trend holds, Hairy Woodpecker in Sierra Nevada is projected to fall about 24% by 2029 — from 3.6 in 2024 to a central estimate of 2.7 (95% range 1.2–4.3). A 5-year backtest shows a typical error of ±34.5%, with 80% of held-out values landing inside the 95% band.

-24%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 →
2.7Projected 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 →
1.2–4.395% 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 →
±34.5%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, Hairy Woodpecker in Sierra Nevada is projected to fall about 24% by 2029 — from 3.6 in 2024 to a central estimate of 2.7 (95% range 1.2–4.3). A 5-year backtest shows a typical error of ±34.5%, 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 →
20252.61.14.1
20262.71.24.2
20272.71.24.2
20282.71.24.2
20292.71.24.3

Routes In Sierra Nevada

Routes recording Hairy 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 →
ChilcootCALIFORNIA132024
Pollock PinesCALIFORNIA112024
GeneseeCALIFORNIA102024
ChesterCALIFORNIA82016
Forest HillCALIFORNIA62022
WestvilleCALIFORNIA52024
RivertonCALIFORNIA52023
Hat CreekCALIFORNIA52018
LakeshoreCALIFORNIA52024
Eagle LakeCALIFORNIA42024
PlacervilleCALIFORNIA42024
Pine MountainCALIFORNIA42017
Bass LakeCALIFORNIA32019
LumberyardCALIFORNIA32024
Butte MeadowCALIFORNIA32014
GoumazCALIFORNIA32011
Little TruckeeCALIFORNIA32023
WoodfordsCALIFORNIA22024
Greenhorn MtCALIFORNIA22008
Silver CityCALIFORNIA22010
Kings CanyonCALIFORNIA22024
Tuolumne GroveCALIFORNIA22024
SattleyCALIFORNIA22024
Higgins CornCALIFORNIA22023
Meadow ValleyCALIFORNIA22024

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