The marsh rice rat, Oryzomys palustris, is the dominant semi-aquatic rodent living in tidal marshes of the Virginia coastal plain. Described as highly carnivorous, this species is known to consume a range of animal foods, including crustaceans, mollusks, fish, and arthropods, as well as some plant foods. Analysis of stomach contents from rice rats collected from Eastern Shore tidal marshes throughout an annual cycle revealed that all 103 stomachs contained dicots, 82 percent had monocots, 61 percent had crabs and insects, and 38 percent had snails. Thirty-eight percent of stomachs contained foods in all five categories, no stomach was empty or contained fish, and 84 percent of stomachs had amounts of hair, probably ingested during self-grooming. In sum, Virginia rice rats are carnivorous but consume greater amounts of plant foods compared to populations that have been studied in Georgia and Louisiana.
Rose, Robert K. and McGurk, Shannon W.
"Year-round Diet of the Marsh Rice Rat, Oryzomys palustris, in Virginia Tidal Marshes,"
Virginia Journal of Science: Vol. 57
, Article 2.
Available at: http://digitalcommons.odu.edu/vjs/vol57/iss3/2