"Marsh rice rats are among the most common mammals inhabiting tidal marshes of the Gulf and Atlantic coasts. Being good swimmers, diving to 10 m and crossing 300 m stretches of water, and able climbers, these rice rats are suitably equipped for life in an environment where water levels fluctuate. They and Coues's rice rats are carnivores: they prey on crabs, clams, snails, fish, insects, baby turtles, and birds. As opportunistic feeders, they will also eat carrion and even some plant material. In some places, they breed throughout the year, and in other places, they breed from March to October. A litter of five, after a gestation of about 25 days, is typical. In a little over a week, the newborn rats' eyes open and they are beginning to nibble solid food. They are weaned before they are three weeks old. As with many nocturnal rodents, owls are the main predator."
Links:Mammal Species of the WorldClick here for The American Society of Mammalogists species account
Original description: Harlan, R., 1837. Description of a new species of quadruped, of the Order Rodentia, inhabiting the United States; by R. Harlan, M.D. Mus palustris, p. 385. American Journal of Science, 31:385-386.