BirdAnalyst
Species · North Dakota · BBS 2025 Release · 1966–2024

Ruddy Duck Population Trend in North Dakota

All statesWaterfowl

Ruddy Duck in North Dakota has surged: up 240% on the route-weighted index since 1969.

+240%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 →
57YearsYears 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 240% 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 fall about 15% by 2029 — from 8.9 in 2024 to a central estimate of 7.6 (95% range 3.4–12). A 5-year backtest shows a typical error of ±28%, with 100% of held-out values landing inside the 95% band.

-15%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 →
7.6Projected 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 →
3.4–1295% 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 →
±28%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 fall about 15% by 2029 — from 8.9 in 2024 to a central estimate of 7.6 (95% range 3.4–12). A 5-year backtest shows a typical error of ±28%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20257.22.911
20267.33.012
20277.43.112
20287.53.212
20297.63.412

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 →
Braddock9020221988
Wimbledon7220241990
Buchanan3620241967
Wild Rose3620241982
Horsehead Lk3220241980
Edgeley2920231986
Lakota 22820242010
Lakota2120091968
Webster820241992
Niles820241992
Stanley820131996
Danzig 2820242019
Bowman520151969
Walcott420012001
Dunn Center320191970
Denbigh320241973
Montpelier320241995
Forman220221968
Danzig220111982
Cooperstown220241969
Bowesmont219921977
Rolla220181969
Carpio220151972
Gorham220181980
Douglas Crk220242000

Ruddy Duck Population Trend in Other States

arizonacaliforniacoloradoidahoillinoisindianaiowakansasmichiganminnesotamontananebraskanevadanew-mexiconew-yorkohiooklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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