Smithsonian National Museum of Natural History, North American Mammals
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  Rodentia · Cricetidae · Sigmodon fulviventer
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Sigmodon fulviventer

Tawny-bellied Cotton Rat

Order: Rodentia
Family: Cricetidae

Image of Sigmodon fulviventer
Sigmodon fulviventer - lower left (with S. arizonae)
Click to enlarge. (95 kb)

Conservation Status: Least Concern.

The tawny-bellied cotton rat is the largest of the Sigmodon species, and dominates other cotton rats where more than one species occurs. Its back fur has a speckled, "salt and pepper" look, and its underparts are buff-colored, giving it two common names: tawny-bellied and yellow-bellied. The tail is dark and has just enough hair to hide the scales. Like other cotton rats, and voles, the tawny-bellied cotton rat constructs grass-lined paths. Litters of 4 or 6 young are born in nests built from woven grasses. They leave the nest to run around when they are about a week old, and are sexually mature and ready to breed when they are about six weeks old.

Also known as:
Yellow-bellied Cotton Rat

Sexual Dimorphism:

Average: 246 mm
Range: 223-270 mm

Range: 200-222 g


Allen, J.A., 1889.  Notes on a collection of mammals from southern Mexico, with descriptions of new species of the genera Sciurus, Tamias, and Sigmodon, p. 180.  Bulletin of the American Museum of Natural History, 2:165-181.


Mammal Species of the World

Mammalian Species, American Society of Mammalogists' species account

Distribution of Sigmodon fulviventer