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

Double-crested Cormorant Population Trend in North Dakota

All statesWetland birds

Double-crested Cormorant in North Dakota has surged: up 777% on the route-weighted index since 1970.

+777%Since 1970TrendPercent 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 →
42Routes 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 Double-crested Cormorant 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 →

Double-crested Cormorant has surged in North Dakota: up 777% on the route-weighted index since 1970.

Double-crested Cormorant Population Forecast in North Dakota

If the recent trend holds, Double-crested Cormorant in North Dakota is projected to rise about 28% by 2030 — from 7.0 in 2025 to a central estimate of 8.9 (95% range 3.1–15). A 5-year backtest shows a typical error of ±97.5%, with 80% of held-out values landing inside the 95% band.

+28%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 →
8.9Projected 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 →
3.1–1595% 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 →
±97.5%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, Double-crested Cormorant in North Dakota is projected to rise about 28% by 2030 — from 7.0 in 2025 to a central estimate of 8.9 (95% range 3.1–15). A 5-year backtest shows a typical error of ±97.5%, with 80% 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 →
20268.42.514
20278.52.614
20288.72.815
20298.82.915
20308.93.115

Double-crested Cormorant Survey Routes in North Dakota

Routes recording Double-crested Cormorant 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 →
Danzig4320141995
Stanley4320241970
Buchanan3920251967
Edgeley3720252003
Lakota 23220252010
Webster2420241999
Danzig 22220252019
Horsehead Lk2120251982
Abercrombie1320051982
Walcott920172017
Emerado820241980
Montpelier720252000
Carpio620231974
Golva620192018
Wild Rose620251982
Powers Lake620251985
Sheyenne Lk620251980
Cooperstown520221995
Glen Ullin520001988
Lake George420191981
Loraine420191982
Douglas Crk420231986
Forman320251970
Lakota320091979
Regan320251974

Double-crested Cormorant Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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