Double- Crested Cormorants

The population of double-crested cormorants in North America has rebounded tremendously since restriction of pesticides like DDT. We are monitoring double-crested cormorant populations between the Gulf Coast and the Great Lakes to determine changes in the population, where birds are roosting, breeding-site fidelity, survival, and other ecological aspects of their life history. For 13 years we have been banding cormorants on their breeding grounds in Wisconsin on Lake Michigan. In the winter many of these birds move south, using the Mississippi River as a major travel corridor. Increasing populations of double-crested cormorants are increasing conflicts with aquaculture, recreational fisheries, and damage of important habitat for other species. We can improve our strategies for reducing these conflicts by better understanding cormorant movements and population ecology.

How will this data be used?

We are a collaborative team between Mississippi State University and USDA-NWRC. We strive to publish all of our research with the intention that it be used to influence management decisions. We are often called on for input toward improving management. We are using band observation data to monitor cormorant population changes, which are important for influencing cormorant management regulations throughout their range. 

How Can You Participate?

Use the protocol to make observations and record data on cormorants. Submit observations online.