Study Finds Alligators Eat Sharks

Posted on October 18, 2017

Alligator biting tail of a nurse shark

A Kansas State University study has found that alligators predate on sharks. The study found alligators on the Atlantic and Gulf coasts are eating small sharks and stingrays. The researchers say this is the first scientific documentation of a widespread interaction between the two predators.

The research was conducted by James Nifong, postdoctoral researcher with the Kansas Cooperative Fish and Wildlife Research Unit at Kansas State University, and Russell Lowers, wildlife biologist with Integrated Mission Support Services at Kennedy Space Center. A research paper on the study was published here in the journal, Southeastern Naturalist.

Nifgon says, "In the article, we documented alligators consuming three new species of sharks and one species of stingray. Before this, there have only been a few observations from an island off the Georgia coast, but the new findings document the occurrence of these interactions from the Atlantic coast of Georgia around the Florida peninsula to the Gulf Coast and Florida panhandle."

The researchers say that freshwater and saltwater differences do not keep the species apart. Sharks and ray sometimes swim into freshwater areas where they are eaten by alligators. Alligators can also venture into saltier waters for limited amounts of time.

Nifong also says, "Alligators seek out fresh water in high-salinity environments. When it rains really hard, they can actually sip fresh water off the surface of the salt water. That can prolong the time they can stay in a saltwater environment. The findings bring into question how important sharks and rays are to the alligator diet as well as the fatality of some the juvenile sharks when we think about population management of endangered species."

Nifong pumped the stomachs of more than 500 live and alert alligators to learn more about their diet. Researchers also equipped the alligators with GPS transmitters to watch their movements. They found that alligators travel between freshwater sources and estuaries.

Image: U.S. Fish and Wildlife Service J.N. Ding Darling National Wildlife Refuge.