BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Lesser Scaup In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauWaterfowl

Lesser Scaup in Southern Rockies / Colorado Plateau has surged: up 252% on the route-weighted index since 1982.

+252%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 →
30Routes 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 →
42YearsYears 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 →

Lesser Scaup has surged in Southern Rockies / Colorado Plateau: up 252% on the route-weighted index since 1982.

Lesser Scaup In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Lesser Scaup in Southern Rockies / Colorado Plateau is projected to rise about 156% by 2030 — from 0.22 in 2025 to a central estimate of 0.55 (95% range 0.15–0.96). A 5-year backtest shows a typical error of ±49.2%, with 100% of held-out values landing inside the 95% band.

+156%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 →
0.55Projected 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 →
0.15–0.9695% 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 →
±49.2%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, Lesser Scaup in Southern Rockies / Colorado Plateau is projected to rise about 156% by 2030 — from 0.22 in 2025 to a central estimate of 0.55 (95% range 0.15–0.96). A 5-year backtest shows a typical error of ±49.2%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.530.130.94
20270.540.130.94
20280.540.140.95
20290.550.140.95
20300.550.150.96

Routes In Southern Rockies / Colorado Plateau

Routes recording Lesser Scaup 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 →
Rio Grnds RsCOLORADO782024
Mcphee Res.COLORADO122012
DinosaurCOLORADO102012
Main CanyonUTAH92025
M Warner ResUTAH92025
TincupCOLORADO62025
Angel Fire 2NEW-MEXICO62009
Skyline DrivUTAH62002
Willow PeakCOLORADO42025
VernalUTAH42016
WarbonnetWYOMING42017
Moon LakeUTAH32000
ColonaCOLORADO22014
WaldenCOLORADO22016
DoylevilleCOLORADO22025
Dunckley PasCOLORADO22017
PiedraCOLORADO22023
Cochetopa PassCOLORADO22025
Uintah NfUTAH21992
BrookhurstWYOMING21992
Lost LakeCOLORADO12002
TarryallCOLORADO11989
Groundhog RsCOLORADO11995
Ragged Mtn.COLORADO12006
Yellowjacket PassCOLORADO12022

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