Species · Louisiana · BBS 2025 Release · 1966–2024
Double-crested Cormorant Population Trend in Louisiana
Double-crested Cormorant in Louisiana has declined: down 32% on the route-weighted index since 1975.
-32%Since 1975
27Routes In State
43Years
Notable Double-crested Cormorant Trends in Louisiana
No notable trend signals for Double-crested Cormorant in Louisiana. See the full index history below.
Double-crested Cormorant Population Forecast in Louisiana
If the recent trend holds, Double-crested Cormorant in Louisiana is projected to rise about 468% by 2029 — from 0.07 in 2024 to a central estimate of 0.41 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±886.5%, with 100% of held-out values landing inside the 95% band.
+468%Change by 2029
0.41Projected 2029 index
0.00–1.495% range
±886.5%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.42 | 0.00 | 1.4 |
| 2026 | 0.42 | 0.00 | 1.4 |
| 2027 | 0.42 | 0.00 | 1.4 |
| 2028 | 0.42 | 0.00 | 1.4 |
| 2029 | 0.41 | 0.00 | 1.4 |
Double-crested Cormorant Survey Routes in Louisiana
| Creole | 20 | 1987 | 1975 |
| Gran Chenier | 14 | 1982 | 1967 |
| Esther | 9 | 2014 | 1988 |
| Atchafalaya | 4 | 1996 | 1996 |
| Zwolle | 4 | 2023 | 1998 |
| Sabine Nwr 2 | 3 | 2017 | 2009 |
| Morgan City | 2 | 2022 | 2022 |
| Belair | 2 | 2007 | 1995 |
| Sabine Nwr | 2 | 2003 | 1992 |
| Haughton | 1 | 2001 | 1998 |
| Junior | 1 | 1991 | 1988 |
| River Road | 1 | 2024 | 1995 |
| Tensas Nwr | 1 | 2004 | 2004 |
| Bickham | 1 | 1985 | 1985 |
| Baton Rouge | 1 | 2021 | 1996 |
| Hackberry | 1 | 1971 | 1971 |
| Shaw | 1 | 2009 | 1990 |
| Longstreet | 1 | 1990 | 1990 |
| Forked Island 2 | 1 | 2010 | 2010 |
| Glencoe | 1 | 1998 | 1998 |
| Ramah | 1 | 2012 | 1993 |
| Kaplan | 1 | 2019 | 2001 |
| Woodlawn | 1 | 2018 | 2016 |
| Port Allen | 1 | 2011 | 2003 |
| Frogmore | 1 | 2024 | 2024 |
Double-crested Cormorant Population Trend in Other States
alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.