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marsh rice rat

marsh rice rat (Oryzomys palustris) Photo coming soon.

Features and Behaviors

The marsh rice rat is about four and three-fourths inches in head-body length with a tail that is about as long as or longer than the head-body length. It has a slender body with gray-brown fur and white feet. The belly fur is gray. The tail is gray-brown above and gray below. The ears are hairy.

The marsh rice rat may be found in the southern one-fourth of Illinois living in marshes and swamps. Its diet usually includes seeds and leaves of grasses and aquatic plants, but it may also eat turtles, fishes, bird eggs, small mammals, insects and snails. This rodent is mainly nocturnal and is active all year. It is a good swimmer. While on land, it makes and uses runways. Mating occurs throughout the spring and summer. Young are raised in a nest of grasses and vines that is placed above flood level. Litter size varies from three to five. Young marsh rice rats reach maturity in about two months.

Illinois Range


Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Cricetidae

Illinois Status: common, native