775.

Meyer’s Giant Rat

Lenomys meyer

French: Rat de Meyer / German: Kleezahn-Riesenratte / Spanish: Rata gigante de Meyer

Other common names: Meyer's Lenomys, Trefoil-toothed Giant Rat

Taxonomy. Mus meyeri Jentink, 1879,

Menado, NE peninsula, Sulawesi, Indonesia.

Lenomysis closely related to Eropeplus and is an old endemic genus of Sulawesi. Lenomys meyeri has not been included in any phylogenetic studies, and its placement in Murinae has not been done before, but based on close morphological characteristic with Eropeplus, itis included here in Rattini . Lenomys grovesi was recently described with subfossil remains from south-western Sulawesi; it could be extant, but there are no recent specimens. T. F. Flannery in 1995 identified a a rat, with shaggy pelage and long bicolored tail, from Pulau Sangir as L. meyeri, but it apparently represents an undescribed species related to mainland Rattus xanthurus; its specific status is still unresolved. Monotypic.

Distribution. N, C & SW Sulawesi; possibly SE Sulawesi.

Descriptive notes. Head-body 235-301 mm, tail 240-298 mm, ear 24-28 mm, hindfoot 46-50 mm; weight 320-325 g. Meyer’s Giant Rat is one of the largest rats on Sulawesi, being rather bulky and very similar to Eropeplus, although it islarger. Pelage is silky, soft, woolly, shaggy, and fairly long, but it can be shorter and harsher. Dorsum is grayish brown to dark brownish gray. Dorsal and ventral pelage are demarcated but notsharply. Venter is whitish gray or grayish white, with graybases on hairs and unpigmented tips. Feet are brown ontop, unpigmented on bottom; claws are stout and unpigmented. Whiskers are shorter and black, and ears are small, rounded, and dark. Tail is 97-103% of head-body length—shorter than in Sulawesi Soft-furred Rat ( Eropeplus canus)—and dark brownish gray, with about one-third of distal part white and covered with thick fur at base. Tail of a specimen from Rano Rano had strongly buffy and thinner pale part on underside and white longer part of tail. Females have two pairs of inguinal mammae. Skull is noticeably larger than that of Eropeplus, with wider zygomatic arches, thinner interparietals, and more smoothly inflated auditory bullae. Spermatozoa have symmetrical club-shaped head, with very shorttail attached to mid-basal part of head.

Habitat. [Lowland to upper montane tropical moist forests from sea level to elevations of ¢.1160 m.

Food and Feeding. Meyer’s Giant Rat is folivorous, insectivorous, and coprophagous, probably foraging at night in understory. Two captured individuals had eaten katydids, grasshoppers, and moths (usually eating everything except legs and wings); large and small fruit from several species of figs ( Ficus spp., Moraceae); small and youngtender green plants,tips of fern fronds, palm heart (mostly thin embryonic leaves); and bait (peanut butter, raisins, oatmeal, and bacon ground into mash). Tougher leaves of sapling or understory trees and several kinds of non-fig fruits were rejected. It required constant drinking water and consumed its own feces, either by taking pellets after they had been deposited or by directly taking them from its anus.

Breeding. A captive Meyer's Giant Rat gave birth to one young that opened its eyes at 17 days old and moved around the cage at 21 days old.

Activity patterns. Meyer’s Giant Rats are nocturnal, seeking refuge during the day in burrows 45 cm deep, leading in to oval chamber 30 cm long and 20 cm in diameter. Chamber is open at night but is covered with dry leaves at night, which makes a bowllike structure. They are primarilyterrestrial but probably forages in the understory.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Meyer's Giant Rathas a relatively wide distribution, but its population is probably decreasing at lower elevations due to human encroachment, but it isstable at higher elevations. It is very hard to trap because ofits folivorous feeding habits, so museum specimens are rare. More research is needed onits natural history to fully understand its conservation.

Bibliography. Breed & Musser (1991), Cassola (2016ac), Flannery (1995a), Maryanto et al. (2009), Musser (1984, 2015), Musser & Carleton (2005), Musser & Durden (2002), Pages et al. (2016).