631.

Ryukyu Islands Tree Rat

Diplothrix legata

French: Rat des Ryukyu / German: Ryukyu-Ratte / Spanish: Rata arboricola de Ryukyu

Other common names: Ryukyu Long-tailed Giant Rat, Ryukyu Rat

Taxonomy. Lenothrix legata Thomas, 1906,

“Oshima, northern group of Liu Kiu Is-lands [= Ryukyu Islands],” Japan.

The recent phylogeny of S. J. Steppan and J.J. Schenk in 2017 found D. legata as sister to a clade of Nesokia + Bandicota in Rattini . Monotypic.

Distribution. Amami Oshima, Tokunoshima, and Okinawa(Ryukyu Is), S Japan.

Descriptive notes. Head-body 230 mm, tail 246 mm, ear 23 mm, hindfoot 49 mm; weight 570-587 g. Adult Ryukyu Islands Tree Rats have very long pelage, scattered with long dorsal guard hairs (longer than 50 mm) and some bristle hairs on back. Adult dorsum is yellowish brown, and venter is whitish or grayish. Tail is long and bicolored, with white distal one-half and dark gray proximal one-half part; it is covered by hair, very distinctive in the Rattus division. Forefeet and hindfeet are massive, covered with short grayish hair, and have pinkish gray skin.

Habitat. Primary forests of oaks and chinquapins at elevations of 300-400 m.

Food and Feeding. The Ryukyu Islands Tree Rat eats insects and seeds.

Breeding. Sexually mature male and female Ryukyu Islands Tree Rats have been found year-round. Males have seminiferous tubule size that varies from small in April-August to large in September—February. Pregnant females were not collected in a road-kill study but potential litters of 2-12 young were suggested by counts of corpora lutea, placental scars, and elongated teat proxy.

Activity patterns. Ryukyu Islands Tree Rats are nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. Deforestation, predation by feral species (e.g. dogs and mongooses), and commensal species are major threats of the Ryukyu Islands Tree Rat. Road-killed rats were also reported by the Ministry of the Environment, Japan.

Bibliography. Ellerman (1941), Ito (1997), Iwasa (2009), Misonne (1969), Musser & Carleton (2005), Okano & Onuma (2015), Okano etal. (2015), Steppan & Schenk (2017), Thomas (1906g, 1916f).