Rice-field Rat (Rattus argentiventer)
Rice field Rat can be found throughout Southeast Asia consists of Indochina region, Thailand, Peninsular Malaysia, Indonesia, Philippine, and New Guinea as major rodent pest in rice field area.
The Rice-field Rat is a medium-sized rat with a grizzled yellow-brown and black pelage. Its belly is gray in the midline with whiter flanks. The tail is uniformly medium brown. They have chisel-like incisor. The Rice-field Rat is between 304-400mm long with a tail length of 140-200mm and a skull length of 37-41mm. The average weight of Rattus argentiventer is around 97 to 219 g. Female have 12 mammae. Young have an orange-coloured tuft in front of each ear.
Rice-field rat lives in large groups which consist of a dominant male and high ranking female. When attacked or disturbed they will make squeals and whistles sound. Rattus argentiventer's main diet includes termites, insects, grasshopper, snails, seeds, nuts, rice, vegetables and fruits. They feed at night and actively moving at dusk and dawn. During daytime, they can be seen among vegetation, weeds or maturing field. Rice-field rat undergoes 3 week gestation giving birth about 5 to 10 young per litters. Parasites of Rice-field Rat include: Schistosoma spindale
Rattus argentiventer is polyoestrous 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)
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)
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.