BirdAnalyst
Species · North Dakota · BBS 2026 Release · 1966–2025

Ruddy Duck Population Trend in North Dakota

All statesWaterfowl

Ruddy Duck in North Dakota has surged: up 165% on the route-weighted index since 1969.

+165%Since 1969TrendPercent 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 →
33Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ruddy Duck Trends in North DakotaNotable 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 →

Ruddy Duck has surged in North Dakota: up 165% on the route-weighted index since 1969.

Ruddy Duck Population Forecast in North Dakota

If the recent trend holds, Ruddy Duck in North Dakota is projected to rise about 41% by 2030 — from 5.3 in 2025 to a central estimate of 7.5 (95% range 3.3–12). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.

+41%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 →
7.5Projected 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 →
3.3–1295% 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 →
±33.4%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, Ruddy Duck in North Dakota is projected to rise about 41% by 2030 — from 5.3 in 2025 to a central estimate of 7.5 (95% range 3.3–12). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20267.12.811
20277.23.011
20287.33.112
20297.43.212
20307.53.312

Ruddy Duck Survey Routes in North Dakota

Routes recording Ruddy Duck in North Dakota.
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 →
Lakota 24920252010
Horsehead Lk4520251980
Edgeley2920231986
Lakota2120091968
Wild Rose1220251982
Buchanan1120251967
Wimbledon920251990
Cooperstown820251969
Webster820241992
Niles820241992
Stanley820131996
Danzig 2820242019
Denbigh620251973
Bowman520151969
Walcott420012001
Dunn Center320191970
Forman220221968
Danzig220111982
Bowesmont219921977
Rolla220181969
Carpio220151972
Gorham220181980
Douglas Crk220242000
Sheyenne Lk220251980
Braddock220231988

Ruddy Duck Population Trend in Other States

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