Rajah Spiny Rat (Maxomys rajah)


The Rajah Spiny Rat (Maxomys rajah) also known as the Brown Spiny Rat is endemic to Thailand and Malaysia, Sumatra, Borneo and the adjacent islands (Payne et al., 1985). Corbet and Hill (1992) mention that Maxomys rats are often the most common rodent in the Southeast Asian tropical forest, from most of the Malay Archipelago to Sulawesi, Palawan and Borneo. This species can be found in primary forest and logged-over forest. According to Payne et al.,(1985) this species lives in primary or secondary forest and tends to favour sandy and lowland sites. This terrestrial species is mostly active on the ground but occasionally climbs into the upper canopy. Its tend to live separately from other rats. M. rajah is medium in size where the upperparts are brown, darker in the midline, with numerous stiff gray-brown spines. The underparts are white with many short, white spines, and usually with a dark brown streak along the middle in adults, but never with an orange throat patch. The white colour of the underparts extend down in a narrow line to the feet. Above the tail is brown, pale below and thinly haired. Usually, the range of the measurement of M. rajah are HB 138.1-218, T 142-210, T/HB = 102.9-109.3%, HF 33.8-43, E 21.9-22.3, Wt 71-218 g, D 1003/1003=16, M 2+2=8. Skull: gl 40.9-48.6, iob 6.6-7.4, mt 6.9-8.1.The immature Red Spiny Rats, M. surifer is similar M. rajah and quite difficult to distinguish. (Payne et al., 1985). M.rajah is a common species but Yasuda et al., (2000) reported that very little is known about the ecological features of Maxomys rats. The smooth pads and long hind feet suggest a scampering gait along the forest floor.

Taxonomic Notes:

Once regarded as conspecific with M. surifer (Ellerman and Morrison-Scott 1951; Misonne 1969), but occurs sympatrically with that species, and although samples of each are regularly misidentified, the two differ in a suite of morphological, ecological, behavioural, and biochemical traits, as well as albumin immunology (Chan et al. 1979, Corbet and Hill 1992, Musser et al. 1979, Yong 1972, Watts and Baverstock 1994).

Range Description:

This species is found in Peninsular Thailand south of the Isthmus of Kra, Peninsular Malaysia, Riau Archipelago, Sumatra, and the island of Borneo (Brunei, Malaysia and Indonesia). It has been recorded from sea level to 1,100 m.
Countries: Native:
Brunei Darussalam; Indonesia; Malaysia; Thailand


 It is common in appropriate habitat. Md Nor (2001) recorded 34 specimens between 500 and 1,100 m on Mt. Nuang, Hulu Langat, Selangor province (Malaysia).
Population Trend: Decreasing

Major Threat(s):

 It is threatened by habitat loss, largely through commercial logging and the conversion of land to agricultural use.

Conservation Actions:

It is present in many protected areas.