716.

New Guinea Slender Rat

Rattus verecundus

French: Rat discret / German: Schlanke Neuguinea-Ratte / Spanish: Rata de Nueva Guinea esbelta

Other common names: Slender Rat

Taxonomy. Mus verecundus Thomas, 1904,

“Avera, Aroa River [Central Province], British New Guinea [= Papua New Guineal.”

Rattus verecundus is part of a clade includ-

ing the other Recent New Guinea native

species of Rattus . It previously included R. vandeuseni, but it is recognized as a distinct species here until further research is conducted. It probably represents a complex of three distinct species as it is currently defined. Three subspecies recognized.

Subspecies and Distribution.

R.v.verecundusThomas,1904—SENewGuinea.

R.v.mollisRummler,1935—C&ENewGuinea.

R. v. unicolor Rimmler, 1935 — W New Guinea.

Descriptive notes. Head-body 123-168 mm (males) and 146-165 mm (females), tail 143-170 mm (males) and 143-171 mm (females), ear 14-6-19-5 mm (males) and 18:1-20-4 mm (females), hindfoot 31:2-33-5 mm (males) and 30-6-34-5 mm (females); weight 88-118 g (males) 100-133 g (females). The New Guinea Slender Ratis small and unique, with relatively long, shiny, smooth, and soft pelage, typically without any spines; nominal subspecies usually has fine small spines throughout dorsal pelage. Dorsum is medium to dark brown, even up to blackish brown. Juveniles have darker and less rufous dorsal pelage and grayer ventral pelage without spines. Venteris light to dark gray, tinged with rust or yellow and is not sharply demarcated from dorsal pelage. White pectoral marking is common. Feet are long and narrow, being white or white mixed with brown hair dorsally and mid-dorsally, respectively. Ears are relatively inconspicuous and dark brown; vibrissae are relatively short. Tail is equal to or longer than head-body length (c.105 mm on average) and dark brown, usually with white tip varying in size, although this is not present in all individuals. Skull is smooth in contour and has large cranium in proportion to size of rostrum. Subspecies mollis is the smallest, verecundus has spines, and unicolor is the largest. The mite genus Echinolaelaps has been recorded on the New Guinea Slender Rat. There are three pairs of mammae: one pectoral and two inguinal. Diploid number is 2n = 32.

Habitat. Wide variety of habitats from primary tropical moist forest to rural gardens with dense coverat elevations of 150-2700 m. The New Guinea Slender Rat also occurs in limestone caves at high elevations.

Food and Feeding. The New Guinea Slender Rat eats insects and seeds.

Breeding. Breeding starts in late October and ends by late May on Mount Erimbari, but births have been recorded in March-April, May-June, and September—-December in other places. Litters have 1-3 young, with two being most common.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The New Guinea Slender Rat has a wide distribution and presumably large and stable overall population, although its survival rate is low compared to other rodents (e.g. Common Lowland Mosaic-tailed Rat, Paramelomys platyops) in its distribution.

Bibliography. Dennis & Menzies (1978), Dwyer (1978), Flannery (1995b), Kale etal. (2012), Musser & Carleton (2005), Robins et al. (2014), Strandtmann & Mitchell (1963), Taylor et al. (1982), Wright et al. (2016).