BirdAnalyst
Species · Nevada · BBS 2026 Release · 1966–2025

Lesser Scaup Population Trend in Nevada

All statesWaterfowl

Lesser Scaup in Nevada has fallen sharply: down 52% on the route-weighted index since 1991.

-52%Since 1991TrendPercent 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 →
8Routes 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 →
27YearsYears 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 NevadaNotable 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 declinecomputed 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 fallen sharply in Nevada: down 52% on the route-weighted index since 1991.

Lesser Scaup Population Forecast in Nevada

If the recent trend holds, Lesser Scaup in Nevada is projected to rise about 96% by 2030 — from 0.19 in 2025 to a central estimate of 0.37 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±50.2%, with 100% of held-out values landing inside the 95% band.

+96%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 →
0.37Projected 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 →
0.00–1.095% 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 →
±50.2%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 Nevada is projected to rise about 96% by 2030 — from 0.19 in 2025 to a central estimate of 0.37 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±50.2%, 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 →
20260.370.001.0
20270.370.001.0
20280.370.001.0
20290.370.001.0
20300.370.001.0

Lesser Scaup Survey Routes in Nevada

Routes recording Lesser Scaup in Nevada.
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 →
Ruby Valley 2620162004
Bald Mtn.420251992
Dobbin Creek419851985
Dinner Sta219911991
Cortez220161968
Sheldon Nwr120092009
Ruby Valley119991999
Virgin Creek120131999

Lesser Scaup Population Trend in Other States

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