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Species · Mississippi · BBS 2026 Release · 1966–2025

Double-crested Cormorant Population Trend in Mississippi

All statesWetland birds

Double-crested Cormorant in Mississippi has surged: up 19× on the route-weighted index since 2008.

19×Since 2008TrendPercent 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 →
10Routes 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 →
18YearsYears 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 MississippiNotable 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 Mississippi: up 19× on the route-weighted index since 2008.

Double-crested Cormorant Population Forecast in Mississippi

If the recent trend holds, Double-crested Cormorant in Mississippi is projected to fall about 26% by 2030 — from 2.2 in 2025 to a central estimate of 1.6 (95% range 0.72–2.6). A 5-year backtest shows a typical error of ±48.9%, with 40% of held-out values landing inside the 95% band.

-26%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 →
1.6Projected 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 →
0.72–2.695% 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 →
±48.9%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 Mississippi is projected to fall about 26% by 2030 — from 2.2 in 2025 to a central estimate of 1.6 (95% range 0.72–2.6). A 5-year backtest shows a typical error of ±48.9%, with 40% of held-out values landing inside the 95% band.20062030
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 →
20261.30.412.2
20271.40.482.3
20281.50.562.4
20291.60.642.5
20301.60.722.6

Double-crested Cormorant Survey Routes in Mississippi

Routes recording Double-crested Cormorant in Mississippi.
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 →
Eagle Lake4020252012
Moon1420192015
Dundee1020192010
Isola520212007
Tchula 3520232007
Delta N.F.120152015
Trace Madison120192019
Macon120252013
Aberdeen120252012
Waynesboro120062006

Double-crested Cormorant Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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