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

Double-crested Cormorant Population Trend in North Carolina

All statesWetland birds

Double-crested Cormorant in North Carolina has surged: up 147% on the route-weighted index since 1979.

+147%Since 1979TrendPercent 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 →
40Routes 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 →
45YearsYears 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 CarolinaNotable 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 Carolina: up 147% on the route-weighted index since 1979.

Double-crested Cormorant Population Forecast in North Carolina

If the recent trend holds, Double-crested Cormorant in North Carolina is projected to rise about 414% by 2029 — from 0.06 in 2024 to a central estimate of 0.29 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±123.7%, with 80% of held-out values landing inside the 95% band.

+414%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 →
0.29Projected 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 →
0.00–1.095% 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 →
±123.7%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, Double-crested Cormorant in North Carolina is projected to rise about 414% by 2029 — from 0.06 in 2024 to a central estimate of 0.29 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±123.7%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.290.001.0
20260.290.001.0
20270.290.001.0
20280.290.001.0
20290.290.001.0

Double-crested Cormorant Survey Routes in North Carolina

Routes recording Double-crested Cormorant in North Carolina.
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 →
Maple Hill2720232017
Washington1620212006
Hertford1220132013
Supply1120211994
Mashoes819821982
Kinston720161984
Sawmill620012001
Dortches520152015
Jarvisburg519991999
Merrimon420211979
Old Trap320172016
Myrtle Grove220241970
Speed220131992
Arcola220221982
Osmond220022002
Jamesville220151983
Waco220002000
Shallotte119901990
Wards Corner120162016
Broad Creek120222000
Rose120001997
Climax120182017
Mooresville119871987
Spring Hope120232005
California120131983

Double-crested Cormorant Population Trend in Other States

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

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