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Species · Washington · BBS 2026 Release · 1966–2025

Williamson's Sapsucker Population Trend in Washington

All statesForest birds

Williamson's Sapsucker in Washington has surged: up 528% on the route-weighted index since 1982.

+528%Since 1982TrendPercent 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 →
15Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Williamson's Sapsucker Trends in WashingtonNotable 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 →

Williamson's Sapsucker has surged in Washington: up 528% on the route-weighted index since 1982.

Williamson's Sapsucker Population Forecast in Washington

If the recent trend holds, Williamson's Sapsucker in Washington is projected to stay roughly flat through 2030, near 0.36 (95% range 0.21–0.51). A 5-year backtest shows a typical error of ±31%, with 60% of held-out values landing inside the 95% band.

-9%Change by 2030TrendPercent 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 →
0.36Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.21–0.5195% 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 →
±31%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 Washington is projected to stay roughly flat through 2030, near 0.36 (95% range 0.21–0.51). A 5-year backtest shows a typical error of ±31%, with 60% of held-out values landing inside the 95% band.19802030
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 →
20260.340.180.48
20270.340.190.49
20280.350.200.50
20290.350.200.51
20300.360.210.51

Williamson's Sapsucker Survey Routes in Washington

Routes recording Williamson's Sapsucker in Washington.
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 →
Omak Creek920241996
Blewett Pass820251992
Carlton520221995
Cloverland520251997
E. Mt. Adams320251997
Ronald120251991
Mazama120012001
Twisp120052005
Laurier120162004
L. Wenatchee120021994
Spring Lake120251985
Rimrock120251980
Curlew119921992
Winthrop119831983
Twin Lakes119871987

Williamson's Sapsucker Population Trend in Other States

arizonacaliforniacoloradoidahomontananevadanew-mexicooregonutahwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.