BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Williamson's Sapsucker In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Williamson's Sapsucker in Southern Rockies / Colorado Plateau has surged: up 496% on the route-weighted index since 1972.

+496%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 →
80Routes 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 →
52YearsYears 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 Southern Rockies / Colorado Plateau: up 496% on the route-weighted index since 1972.

Williamson's Sapsucker In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Williamson's Sapsucker in Southern Rockies / Colorado Plateau is projected to rise about 43% by 2029 — from 0.20 in 2024 to a central estimate of 0.29 (95% range 0.12–0.45). A 5-year backtest shows a typical error of ±25%, with 100% of held-out values landing inside the 95% band.

+43%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 →
0.29Projected 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 →
0.12–0.4595% 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 →
±25%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 Southern Rockies / Colorado Plateau is projected to rise about 43% by 2029 — from 0.20 in 2024 to a central estimate of 0.29 (95% range 0.12–0.45). A 5-year backtest shows a typical error of ±25%, 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 →
20250.280.110.44
20260.280.110.44
20270.280.120.45
20280.280.120.45
20290.290.120.45

Routes In Southern Rockies / Colorado Plateau

Routes recording Williamson's Sapsucker in Southern Rockies / Colorado Plateau.
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 →
TsaileARIZONA62023
PowderhornCOLORADO62023
Dixie NfUTAH62024
Pinos CreekCOLORADO51989
FlattopsCOLORADO52016
Deadman Rd.COLORADO32024
Wet Mtns.COLORADO32018
Comanche PkCOLORADO32022
ComoCOLORADO32016
Marshall PasCOLORADO32014
Cochetopa PassCOLORADO32007
Haycamp MesaCOLORADO32024
BeckUTAH31973
Heber Mtn.UTAH32022
Lost Cr. ResUTAH32009
Red Spur Mtn.UTAH32023
SawmillARIZONA22006
Pagosa SpgsCOLORADO21982
Lost LakeCOLORADO21999
Blackhead PkCOLORADO22014
Buffalo ParkCOLORADO22023
Fox CreekCOLORADO22011
CokedaleCOLORADO22003
Stillwater PassCOLORADO22009
LudlowCOLORADO22011

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