In her study, Isadore refers to river otters as “opportunistic predators whose diet varies seasonally according to availability of prey species.”
River otters are small and typically measure up to two-and-a-half feet to five feet long. They eat fish, crabs, birds, reptiles and frogs, according to the National Wildlife Federation.
Brown pelicans, meanwhile, can grow up to five feet in length, with a wingspan measuring anywhere from six-and-a-half feet to seven-and-a-half feet long,
The first instance of a river otter eating a brown pelican was at the Rodeo Lagoon in 2006, about 50 miles from Abbotts Lagoon, according to the study.
During one season at Abbotts Lagoon, Isadore and her co-author, Terrence Carroll, counted 73 pelican carcasses, according to the study.