Reithrodontomys fulvescensfulvous harvest mouse

Geographic Range

Reithrodontomys fulvescens can be found in southeast Arizona, southwest and east Texas, east Oklahoma, southeast Kansas, southwest Missouri, west Arkansas, Louisiana, and west Mississippi (Whitaker, J.O. Jr. 1980, Davis and Schmidly 1994).


This mouse occurs mostly in low grassy or weedy areas or along creek bottoms with tangled vines and bushes. In southern areas, R. fulvescens lives in "arid inland valleys where temperatures are high and the soil is sandy or rocky" (Hall and Kelson 1959).

Physical Description

This mouse resembles the house mouse but differs in its hairier tail and grooved upper incisors (Nowak 1991). The length of the tail is greater than half of the total body length (Whitaker, Jr. 1980). Ears of R. fulvescens are large. The hair on the upper body is a mixture of reddish brown and black, creating a salt and pepper effect (Hall and Kelson 1959). R. fulvescens has a tail that is much longer than its body and its under parts are white to buff. The adult plumage is brighter than that of the juvenile and adults molt once a year. Females have six mammae. A typical harvest mouse weighs about 18 grams.

  • Average mass
    18 g
    0.63 oz


Peaks in reproduction for R. fulvescens occur in late spring and early autumn with a breeding season that extends from February all the way through to October. The gestation period is approximately twenty days with an average litter size of about three or four. Each newborn weighs about one gram. By the second week, the young are well-furred and by about nine to twelve days, the eyes are open (Davis and Schmidly 1994). At three weeks, the young leave the nest and by five weeks, they are at full size (Grzimek 1990).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual


Perhaps the most fascinating habit of the fulvous harvest mouse is its ability to build large, above-ground "penthouses" in grasses, low shrubs, or small trees (Davis and Schmidly 1994). These may be constructed of the materials in the animal's habitat or may be converted bird's nests. The solid, globe-shaped nest has one or two exits near the bottom end which can be clogged up. Sometimes, R. fulvescens makes use of the burrows of other animals, although it does not make its own. R. fulvescens is nocturnal.

Communication and Perception

Food Habits

The diet of R. fulvescens mainly consists of seeds, the green shoots of vegetation and some insect larvae. The fulvous harvest mouse seems to enjoy butterfly larvae (Grzimek 1972, Grzimek 1990).

Conservation Status


Emily Rosenblum (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


uses touch to communicate

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


"Encyclopedia Britannica Online" (On-line). Accessed October 4, 1999 at

Davis, W., D. Schmidly. 1994. The Mammals of Texas. Austin: Texas Parks and Wildlife.

Grzimek, B. 1990. Grzimek's Encyclopedia of Animals 3. South Orange: McGraw-Hill Publishing Co..

Grzimek, B. 1972. Grzimkek's Animal Life Encyclopedia II. London: Van Nostrand Reinhold Company.

Hall, E., K. Kelson. 1959. The Mammals of North America 11. New York: Ronald Press Company.

Nowak, R. 1991. Mammals of the World. Baltimore: Johns Hopkins University Press.

Whitaker, Jr., J. 1980. The Audubon Society Field Guide to North American Mammals. New York: Alfred A. Knopf.