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

Lesser Scaup Population Trend in Montana

All statesWaterfowl

Lesser Scaup in Montana has held roughly steady: down 0% on the route-weighted index since 1975.

-0%Since 1975TrendPercent 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 →
50Routes 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 →
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 Lesser Scaup Trends in MontanaNotable 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 Montana. See the full index history below.

Lesser Scaup Population Forecast in Montana

If the recent trend holds, Lesser Scaup in Montana is projected to fall about 10% by 2030 — from 0.37 in 2025 to a central estimate of 0.33 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±129.5%, with 100% of held-out values landing inside the 95% band.

-10%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 →
0.33Projected 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 →
0.00–1.795% 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 →
±129.5%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 Montana is projected to fall about 10% by 2030 — from 0.37 in 2025 to a central estimate of 0.33 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±129.5%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.370.001.8
20270.360.001.7
20280.350.001.7
20290.340.001.7
20300.330.001.7

Lesser Scaup Survey Routes in Montana

Routes recording Lesser Scaup in Montana.
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 →
Roy1120251993
Virgelle1019791979
Westby920242015
Whitlash920242009
Red Rock720251980
Cleveland620131979
Ingomar620251978
Willow Creek 2520061992
Highwood520111976
Sun River520192019
St Mary419971985
Augusta420241977
East Glacier Park420192017
Dinosaurs H.M.420252019
Great Falls319801972
Leroy320171994
Flatwillow319901978
Ester Lake320242015
Harlem219931985
Oswego219781978
Redstone219901990
Brusett219891989
Jordan219871987
Circle219941969
Shawmut220231982

Lesser Scaup Population Trend in Other States

alaskacaliforniacoloradoidahoiowakansasmichiganminnesotanebraskanevadanew-mexiconorth-dakotaoregonsouth-dakotautahwashingtonwisconsinwyoming

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