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Species · Montana · BBS 2025 Release · 1966–2024

Williamson's Sapsucker Population Trend in Montana

All statesForest birds

Williamson's Sapsucker in Montana has declined: down 43% on the route-weighted index since 1972.

-43%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 →
26Routes 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 →
41YearsYears 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 MontanaNotable 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 Montana. See the full index history below.

Williamson's Sapsucker Population Forecast in Montana

If the recent trend holds, Williamson's Sapsucker in Montana is projected to stay roughly flat through 2029, near 0.14 (95% range 0.00–0.29). A 5-year backtest shows a typical error of ±235.4%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.14Projected 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 →
0.00–0.2995% 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 →
±235.4%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 Montana is projected to stay roughly flat through 2029, near 0.14 (95% range 0.00–0.29). A 5-year backtest shows a typical error of ±235.4%, 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 →
20250.130.000.28
20260.140.000.28
20270.140.000.29
20280.140.000.29
20290.140.000.29

Williamson's Sapsucker Survey Routes in Montana

Routes recording Williamson's Sapsucker in Montana.
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 →
Greenough720041999
Greenoagh 2720112005
St Regis319821982
Victor220011994
Elevation Mt220221996
Clinton219721972
Swan Lake220162015
Greenoagh 3220212014
Noxon220232001
Libby Dam119811981
Threemile Wa120132004
Cramer Creek120192000
Pryor Mtn.120122002
Arlee120191969
Woodman120211990
Inside Road120152014
Sula120241986
Reed Point120092009
Whitefish Lake120222017
Red Rock120061996
Skalkho-Rye120162000
Ninemile120222003
Fish Creek120242024
Skalkaho119961992
Hebgen Lake120242017

Williamson's Sapsucker Population Trend in Other States

arizonacaliforniacoloradoidahonevadanew-mexicooregonutahwashingtonwyoming

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