Rattus argentiventerrice-field rat

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Geographic Range

Rattus argentiventer is found throughout Southeast Asia.

Habitat

Rice field rats primarily reside in cultivated areas such as rice paddies and grasslands. It is largely dependent on human rice fields and plantations. Rice field rats shelter in burrows in soil, under rocks, and in logs. They make nests from hollowed-out heaps of material, often in a burrow. (Nowak 1991, Barnett 1975)

Physical Description

Rattus argentiventer is a medium-sized rat with grizzed yellow-brown and black pelage that is not spiny when stroked. Its belly is grayish in the midline with whiter flanks. The dorsal sufaces of its hind feet are about the same color as its back and often have a dark spot or line. The tail is uniformly medium brown. Rattus argentiventer is 304-400mm long with a tail length of 140-200mm and a skull length of 37-41mm. (Van Peenen 1969)

Reproduction

Rattus argentiventer is polyestrous with a 4 to 5 day estrus and a continuous breeding season. Gestation lasts 3 weeks, with 3 to 8 young per litter and 1 to 12 litters a year. Rice field rats have 12 mammae. Female rats build a nest 3 to 5 days before parturition in which the young are born. They are born naked and blind but fully furred. After 15 days, their eyes open. Weaning occurs and the young leave the nest after 3 weeks. Young Rattus argentiventer reach sexual maturity at 3 months. All young experience maternal care and are reared with their litter mates. The male rat plays little part in the care of the young. (Ansell 1960, Nowak 1991, Hamilton 1939)

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

Behavior

Rattus argentiventer lives in large groups with a social hierarchy of dominant males and a few high ranking females. Groups are territorial. Rattus argentiventer has a vocal repertoire consisting mainly of squeals and whistles used in aggressive encounters. (Nowak 1991)

Communication and Perception

Food Habits

Rattus argentiventer is omnivorous, with a diet that includes termites, grasshoppers, snails, insects, rice, seeds, nuts, vegetables, and fruit. (Nowak 1991, Grzmick 1990)

Economic Importance for Humans: Negative

Rattus argentiventer is often responsible for depredations on rice fields and gardens. It is the fourth most damaging rodent to rice crops. (Grzmick 1990, Nowak 1991)

Conservation Status

Rattus argentiventer has no special conservation status.

Contributors

Susan Kennedy (author), University of Michigan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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.

chemical

uses smells or other chemicals to communicate

endothermic

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.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

motile

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.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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sexual

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

tactile

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.

savanna

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.

References

Barnett, S.A. 1975. The Rat: A Study in Behavior. The University of Chicago Press, Chicago.

Grizmick's Encyclopedia of Mammals. Vol.3. 1990. McGraw-Hill Publishing Company, New York.

Hamilton, N. American Mammals. 1939. McGraw-Hill Book Company Inc., New York.

Nowak, R. Walker's Mammals of the World. 5th ed. Vol II. 1991. The Johns Hopkins University Press, Baltimore.

Van Peenen, P. 1969. Preliminary Identification Manual for Mammals of South Vietnam. United States National Museum Smithsonian Institution, Washington.