315.

Black-tailed Giant Rat

Uromys anak

French: Uromys a queue noire / German: Schwarzschwanz-Riesenratte / Spanish: Rata gigante de cola negra

Other common names: Black-tailed Uromys, Giant Naked-tailed Rat

Taxonomy. Uromys anak Thomas, 1907,

“Ifogi [= Efogi], Brown River, N.E. British New Guinea [= Central Province, Papua New Guinea]. Altitude ‘not less than 4000 ft{=1219mj}.’ ©

Within Uromys, U. anak is placed under subgenus Uromys along with U. boeadui, U. caudimaculatus, U. emmae, U. hadrourus, and U. neobritannicus, on basis of morphology, U. anak seems to be sister to U. neobritannicus . Three subspecies currently recognized.

Subspecies and Distribution.

U.a.anakThomas,1907—ECentralCordillera,NewGuinea.

U.a.albiventerGroves&Flannery,1994—WCentralCordillera,NewGuinea.

U. a. rothschildi Thomas, 1912 — Huon Peninsula, NE New Guinea.

Descriptive notes. Head—body 270-335 mm, tail 228—400 mm, ear 1626-5 mm, hindfoot 61-3-75-5 mm; weight 450-1020 g. The Black-tailed Giant Rat is a very large species of Uromys . Pelage is long and harsh, consisting largely of long dark guard hairs. Dorsal pelage is a shiny black intermixed coarsely with grayish brown with a dark rufous or burnt amber coloration; there is also an ill-defined mid-dorsal line. Ventral pelage is a mix between brown and white and can shade toward one or the other. Feet are black and haired dorsally, being lighter on underside and digits. Ears are relatively long, naked and rounded, while being dark pinkish black; vibrissae are thick and black. Tail is long (c.110% of head-body length) and is distinctly monocolored dark brownish black with small lighter patches, distinguishing it from other Uromys species except for Emma’s Giant Rat ( U. emmae) and the Biak Island Giant Rat (U. boeadu). Subspecies anak is lighter in color with a longer tail, smaller body, and shorter hindfeet; subspecies albiventer is more brown dorsally and more white ventrally; subspecies rothschildi is very dark brownish black dorsally and paler ventrally, but not white, with a larger body and shorter tail. Skull is large and heavy. The nematode genus Odilia has been recorded from this species. There are two pairs of mammae, both inguinal.

Habitat. Found in primary tropical moist forests, as well as degraded and secondary forest, at elevations from 850 m to 3000 m. Black-tailed Giant Rats have been recorded also from caves and Pandanus (Pandanaceae) stands.

Food and Feeding. The Black-tailed Giant Rat seemsto be herbivorous, and has been reported to feed on the nuts of Pandanus and the fruits of Homalanthus (Euphorbiaceae) .

Breeding. Little is known, but a female with four young was captured in a nest in August, while a subadult female was captured in July.

Activity patterns. Black-tailed Giant Rats are probably nocturnal and seem to be arboreal, nesting in large epiphytes, tree hollows or Pandanus, as well as deep in caves on flat leaves placed on muddy shelves.

Movements, Home range and Social organization. Generally, 8-12 individuals can be found together in nests. Black-tailed Giant Rats are fairly aggressive when disturbed or threatened, making growling and snarling sounds when disturbed, and will readily attack by biting when necessary. They will flee nests from high areas byjumping with the arms spread, as if “parachuting” down to the ground, before running off.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Blacktailed Giant Rat has a wide distribution but is considered relatively uncommon, being found at low densities throughout its range. In specific localities, it may be affected by overhunting by natives, although this is relatively localized. It has been found in the Lorentz National Park and probably occurs in other protected areas.

Bibliography. Aplin & Flannery (2017), Bryant et al. (2011), Flannery (1995b), Groves & Flannery (1994), Menzies & Dennis (1979), Musser & Carleton (2005), Smales (2008), Steppan & Schenk (2017).