Tanezumi Rat (Rattus tanezumi)

Range Description:

 Both the native and introduced geographic distribution of this very widespread species remains somewhat unclear. We follow Musser and Carleton (2005) who consider the species native distribution to range from Eastern Afghanistan (Niethammer and Martens 1975) through Central and Southern Nepal (below about 2,000 m asl), Bhutan, Northern India, Northern Bangladesh and North-Eastern India (distributional relationships between R. rattus and R. tanezumi along the Northern portion of the Indian subcontinent still requires resolution) into Southern and Central China (including Hainan Island), the Korean Peninsula, and mainland Southeast Asia (including offshore islands) south to the Isthmus of Kra, being also probably native to Mergui Archipelago. Musser and Carleton (2005) report that it is presently unclear whether the species is native or introduced to Taiwan and Japan. But is most likely introduced to Peninsular Malaysia and islands on the Sunda Shelf and nearby archipelagos, including the Mentawai Islands (Musser and Califia 1982; Musser and Newcomb 1983). It has been introduced to Little Nicobar and Great Nicobar, in the Andaman and Nicobar Islands of India. It has been widely introduced throughout the Philippines (Heaney et al. 1998; Musser and Carleton 2005; Larry Heaney pers. comm.). It appears to have been widely introduced throughout insular Southeast Asia, including the Greater and Lesser Sunda Islands and the Molucca Islands, to Western New Guinea (range map very provisional for this island) (Flannery 1995), and from here into Micronesia to the islands of Eniwetok and Fiji (Musser and Carleton 2005).
Countries: Native:
Afghanistan; Bangladesh; Bhutan; Cambodia; China; India; Japan; Korea, Democratic People's Republic of; Korea, Republic of; Lao People's Democratic Republic; Malaysia; Nepal; Taiwan, Province of China; Thailand; Vietnam
Introduced:
Fiji; Indonesia; Papua New Guinea; Philippines

Description:

 The fur on the dorsal side is olive-brown, and the ventral side generally lighter. The tail is very dark grey and nearly naked. The ears are large and the eyes jet black. Juveniles have a relatively larger head and smaller body. Head-Body Length : Up to 22cm  Tail Length : Up to 22cm  Weight : Up to 200 grams. Rattus tanezumi is the oldest name for the 2n = 42 group of Asian house rats that is distinguished from the 2n = 38/40 Rattus rattus not only by chromosomal characters but also morphological and biochemical traits (Wilson, 2005) Many endoparasites infecting the different viscera of R. tanezumi belong to taxonomic groups Nematoda (roundworms), Cestoda (tapeworms), and Trematoda (flukes). The more important ones are those that are transmissible to humans. In contrast, there have been few reports on the ectoparasites that infest these rats. These are the mites, ticks, and fleas, some of which may serve as vectors of microbial infections to humans and domestic animals. Rattus tanezumi is an alternative meat source for the rural folk. Rat meat is a favourite accompaniment to alcoholic beverages during drinking sprees. Unknowingly, some zoonotic infections can be transmitted to humans through improperly cooked rat meat and viscera, accidental wound contamination with rat urine, or rat bites during handling and precooking preparations
This species is regularly misidentify with Rattus rattus and treated as Rattus rattus species group and often confused in field with Rattus argentiventer, Rattus andamanensis and Rattus tiomanicus .
he species is closely related to the European House Rat Rattus rattus, but recent studies suggest it is a separate species. It probably occurs throughout Southeast Asia.

Population:

It is a common to abundant species.
Population Trend: Increasing

Habitat and Ecology:

This highly adaptable species is commonly found in and around villages and agricultural areas. In the Philippines it is common in disturbed lowland and montane forest up to 1,800 m (Danielsen et al. 1994; Heaney et al. 1989. A supremely adaptable species, is to be found in many man-made habitats including agricultural and wholly urban areas. It is omnivorous, feeding on all manner of farmyard waste and food scraps. It is a fast runner, can climb well and can jump up to 50 cm.
Systems: Terrestrial

Major Threat(s):

 There are no major threats to this species.

Conservation Actions:

 It is presumably present in numerous protected areas. No direct conservation measures are needed for this common and adaptable species. There is a need to further study the taxonomic relationships between populations of Rattus currently allocated to this species.

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