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

Gadwall Population Trend in North Dakota

All statesWaterfowl

Gadwall in North Dakota has surged: up 267% on the route-weighted index since 1969.

+267%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 →
49Routes 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 Gadwall 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 →

Gadwall has surged in North Dakota: up 267% on the route-weighted index since 1969.

Gadwall Population Forecast in North Dakota

If the recent trend holds, Gadwall in North Dakota is projected to rise about 17% by 2029 — from 17 in 2024 to a central estimate of 20 (95% range 11–28). A 5-year backtest shows a typical error of ±20.7%, with 100% of held-out values landing inside the 95% band.

+17%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 →
20Projected 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 →
11–2895% 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 →
±20.7%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, Gadwall in North Dakota is projected to rise about 17% by 2029 — from 17 in 2024 to a central estimate of 20 (95% range 11–28). A 5-year backtest shows a typical error of ±20.7%, 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 →
2025191027
2026191027
2027191128
2028191128
2029201128

Gadwall Survey Routes in North Dakota

Routes recording Gadwall 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 →
Niles5120241989
Stanley4120241969
Sheyenne Lk3620241980
Horsehead Lk3320241980
Braddock3220221988
Forman2620241968
Wild Rose2620241982
Danzig 22620242019
Lakota 22520242010
Wimbledon2320241989
Carpio2320231969
Bowman2320241969
Webster2120241989
Rolla2120241969
Edgeley1920241980
Danzig1720141982
Cooperstown1720241969
Lakota1720091968
Montpelier1720241995
Sydney1619831967
Buchanan1620241967
Powers Lake1020241980
Regan920221968
Douglas Crk820241982
Lake George720221967

Gadwall Population Trend in Other States

alaskaarizonacaliforniacoloradodelawareidahoillinoisiowakansasmassachusettsmichiganminnesotamissourimontananebraskanevadanew-jerseynew-mexiconew-yorkoklahomaoregonpennsylvaniarhode-islandsouth-dakotatexasutahvermontwashingtonwisconsinwyoming

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