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Species · BCR 5 · BBS 2025 Release · 1966–2024

Williamson's Sapsucker In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Williamson's Sapsucker in Northern Pacific Rainforest has declined: down 34% on the route-weighted index since 1976.

-34%Since 1976TrendPercent 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 →
5Routes 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 →
18YearsYears 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 →

No notable trend signals for Williamson's Sapsucker in Northern Pacific Rainforest. See the full index history below.

Williamson's Sapsucker In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Williamson's Sapsucker in Northern Pacific Rainforest is projected to stay roughly flat through 2021, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±68.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2021TrendPercent 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 →
0.02Projected 2021 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1095% 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 →
±68.2%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, Williamson's Sapsucker in Northern Pacific Rainforest is projected to stay roughly flat through 2021, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±68.2%, with 100% of held-out values landing inside the 95% band.19742021
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 →
20170.020.000.10
20180.020.000.10
20190.020.000.10
20200.020.000.10
20210.020.000.10

Routes In Northern Pacific Rainforest

Routes recording Williamson's Sapsucker in Northern Pacific Rainforest.
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 →
ShellrockOREGON32015
Emigrant LkOREGON21980
Mt ShastaCALIFORNIA12012
WhiskeytownCALIFORNIA12006
Elk LakeOREGON12016

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