BirdAnalyst
Species · Utah · BBS 2025 Release · 1966–2024

Lesser Scaup Population Trend in Utah

All statesWaterfowl

Lesser Scaup in Utah has declined: down 47% on the route-weighted index since 1988.

-47%Since 1988TrendPercent 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 →
13Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lesser Scaup Trends in UtahNotable 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 Lesser Scaup in Utah. See the full index history below.

Lesser Scaup Population Forecast in Utah

If the recent trend holds, Lesser Scaup in Utah is projected to rise about 301% by 2029 — from 0.10 in 2024 to a central estimate of 0.41 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±1516.3%, with 100% of held-out values landing inside the 95% band.

+301%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 →
0.41Projected 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 →
0.00–1.295% 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 →
±1516.3%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, Lesser Scaup in Utah is projected to rise about 301% by 2029 — from 0.10 in 2024 to a central estimate of 0.41 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±1516.3%, with 100% of held-out values landing inside the 95% band.19862029
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 →
20250.410.001.2
20260.410.001.2
20270.410.001.2
20280.410.001.2
20290.410.001.2

Lesser Scaup Survey Routes in Utah

Routes recording Lesser Scaup in Utah.
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 →
Skyline Driv620021986
M Warner Res620241993
Neponset Res520171995
Lynn520211995
Vernal420161999
Moon Lake320001994
Main Canyon320182016
Saleratus Cr220151995
Uintah Nf219921988
Bear River219941993
Callao220211999
Grizzly Rdge119981998
Navajo Lake120221990

Lesser Scaup Population Trend in Other States

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