BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Williamson's Sapsucker In Northern Rockies

All regionsNorthern RockiesForest birds

Williamson's Sapsucker in Northern Rockies has surged: up 376% on the route-weighted index since 1972.

+376%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 →
83Routes 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 →
51YearsYears 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 →

Williamson's Sapsucker has surged in Northern Rockies: up 376% on the route-weighted index since 1972.

Williamson's Sapsucker In Northern Rockies Population Forecast

If the recent trend holds, Williamson's Sapsucker in Northern Rockies is projected to fall about 20% by 2029 — from 0.48 in 2024 to a central estimate of 0.39 (95% range 0.18–0.59). A 5-year backtest shows a typical error of ±34.3%, with 100% of held-out values landing inside the 95% band.

-20%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 →
0.39Projected 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 →
0.18–0.5995% 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 →
±34.3%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 Rockies is projected to fall about 20% by 2029 — from 0.48 in 2024 to a central estimate of 0.39 (95% range 0.18–0.59). A 5-year backtest shows a typical error of ±34.3%, 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 →
20250.370.160.57
20260.370.170.58
20270.380.170.58
20280.380.170.59
20290.390.180.59

Routes In Northern Rockies

Routes recording Williamson's Sapsucker in Northern Rockies.
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 →
OchocoOREGON91982
Hash RockOREGON92024
Omak CreekWASHINGTON92024
SilviesOREGON82024
GreenoughMONTANA72004
Greenoagh 2MONTANA72011
BarnhouseOREGON72024
Silver CreekOREGON62024
Spring LakeWASHINGTON62024
CloverlandWASHINGTON62024
DesolationOREGON52007
Donelly 2OREGON52024
PierceIDAHO42003
LogdellOREGON42022
Mount VernonOREGON42024
Sawtooth City 2IDAHO32019
St RegisMONTANA31982
AlbeeOREGON32023
AveryIDAHO21991
Lolo PassIDAHO22007
AlturasIDAHO21985
CoolinIDAHO22018
CabartonIDAHO22003
Sawtooth CtyIDAHO22013
BurgdorfIDAHO22000

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