729.

Indomalayan Long-tailed Giant Rat

Leopoldamys sabanus

French: Rat de Sabah / German: Siidasiatische Langschwanz-Riesenratte / Spanish: Rata gigante de cola larga de Indomalasia

Other common names: Indomalayan Leopoldamys, Long-tailed Giant Rat, Noisy Rat

Taxonomy. Mus sabanus Thomas, 1887,

“Saba [= Sabah], the district of North Bor-neo in which Mount Kina-Balu [= Gunung Kinabalu] stands,”

Malaysia.

Leopoldamys herberti was recently recognized as a distinct species from L. sabanus based on genetic and morphological data. Distribution of L. sabanus has been restricted to the Sundaic region with a northern limit of Kanchanaburi Province, southern Thailand. Leopolamys sabanus is in need of a thorough taxonomic revision because there have been many subspecies recognized and genetic data show that it probably represents a species complex. Remaining mainland populations in southern Thailand and Peninsular Malaysia were recently recognized as a distinct species, L. vociferans, which is not recognized here because a more thorough revision is needed. There are clearly more taxa to delineated within L. sabanus, pending additional research. Two subspecies recognized.

Subspecies and Distribution.

L.s.sabanusThomas,1887—Sumatra,Java,andBorneo,aswellasvarioussmalloffshoreIs.

L. s. vociferans G. S. Miller, 1900 — S Myanmar, S Thailand, Malay Peninsula, and some small offshore Is.

Descriptive notes. Head-body 200-275 mm, tail 270-415 mm, hindfoot 42-52 mm; weight 250-500 g. The Indomalayan Long-tailed Giant Rat is very large, with soft, spiny, and sleek pelage. Dorsum is buffy brown to orangish brown, being darker along spine and brighter orangish brown onsides; guard hairs are shorter than most other species of Leopoldamys . Venter is white to yellowish white, sometimes with more pronounced yellowish hue, and sharply demarcated from dorsum. Feet are brown on top with white toes; hindfeet are long. Ears are long, leathery, and brown; vibrissae are very long. Tail is 135% of head-body length, blotchy brown above and creamy white below, being clearly demarcated; tip of tail is white on some specimens. Skull is large and elongated, typical of the genus. There are four pairs of mammae: one pectoral, one post-axillary, and two inguinal pairs. Nematodes Filarioidea, Globocephalus, Heligmonoides, Mastopharus, Physalopteridae, etc., cestode species Hymenolepis and Rodentolepis, trematode Zonorchis, pentastomide Armillifer, and some ticks Ixodes have been recorded from this species. Chromosomal complement is 2n = 42, FN = 54.

Habitat. Primarily lowland tropical forests, sometimes montane wet tropical forests, and disturbed habitat (e.g. logged forests), preferring drier parts of forests, at elevations of 300-3100 m. The Indomalayan Long-tailed Giant Rat seems to be found at higher elevations on Borneo (3100 m) than in Malaysia (1400 m), and it isapparently found at a different elevation than the Sundaic Mountain Long-tailed Giant Rat (L. cthatus).

Food and Feeding. The Indomalayan Long-tailed Giant Rat generally eats insects, snails, fruit, and other vegetation (including roots and leaves). Foraging occurs in the canopy and on the ground. Food hoarding occurs; in Malaysia, they would hide fruit given to them (oil palm fruit, Elaeis guineensis, Arecaceae), caching it on ground covered with leaves. Camera traps showed that the Indomalayan Long-tailed Giant Rat was attracted to fish oil as bait.

Breeding. Breeding occurs year-round, with peak of pregnant females in July—September, being less common in January-March. Litters have 1-7 young (mean3-1). Young are born in burrows with 1-2 entrances dug into hillsides. Nests are usually lined with broad leaves collected from nearby shrubs and undergrowth.

Activity patterns. The Indomalayan Long-tailed Giant Rat is mainly terrestrial and nocturnal. A recent study found 20 nests underground and four nests aboveground, and another study found 20 nests underground and 14 nests aboveground, indicating preference for nesting on the ground. Ground nests were 40-80 m apart, more commonly 50-80 m. Aboveground nests were located in tree cavities and logs with entrances 1-1-6 m aboveground. The species sleeps in nests during the day and comes out at night. Mean time spent moving at night in one study was 485 minutesin logged and unlogged forests.

Movements, Home range and Social organization. Indomalayan Long-tailed Giant Rats are known to traverse trees to forage. Females and males or females and juveniles are known to stay in the same nests. When moving around at night, paths (determined by radio-tracking data) are relatively straight, and movement averages 32 m/ten minutes, covering areas of 2083-9829 m®. Paths were mostlikely determined by location of resources rather than by sex or habitat type (logged vs. unlogged forest).

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Indomalayan Long-tailed Giant Rat has a wide distribution and is fairly common, being the most common species found in a surveyat Mount Nuangin Selangor, Malaysia. Deforestation might be a threat in regions with prevalent logging, but it commonly occurs in logged forests and is found in many protected areas.

Bibliography. Aplin, Ruedas & Molur (2016), Balakirev, Abramov & Rozhnov (2013), Francis (2008), Gorog et al. (2004), Lah et al. (2015), Latinne, Chaval et al. (2013), Latinne, Waengsothorn et al. (2013), Lim (1970), Madinah etal. (2011), Medway (1969), Musser (1981a), Musser & Carleton (2005), Nor (2001), Ow-Yang (1971), Phillipps & Phillipps (2016), Singh & Cheong (1971), Thanee et al. (2009), Wells, Corlett et al. (2009), Wells, Kalko et al. (2008), Yasuda et al. (2000), Yong (1970).