288.

Greater Ryukyu White-toothed Shrew

Crocidura orii

French: Crocidure d'Orii / German: Grof 3e Ryukyu-WeiRzahnspitzmaus / Spanish: Musarana de Ryukyu mayor

Other common names: Amami Shrew, Orii's Shrew

Taxonomy. Crocidura ori Kuroda, 1924,

Komi, Amami Oshima, Ryukyu Archipelago, Japan.

Crocidura ori is known from less than a handful of specimens, one of which was ob- tained from the stomach of a snake. It was originally described as an insular subspecies of C. dsinezumi —the most common species on the main islands ofJapan. Although sympatrically distributed with C. watasei in Ryukyu Archipelago, these two have differ-

ent origins. In a comprehensive molecular study by S. Dubey and his co-workers in 2008, C. orii was found in the basal position of a so-called Asian clade that comprised most Asian species of Crocidura and Diplomesodon pulchellus. This indicated that C. ori was a relict species, representing one of the most primary lineages in Asia. Monotypic.

Distribution. Endemic to Amami Is, C Ryukyu Is, Japan, including Amami Oshima, Kakeromajima, and Tokunoshima.

Descriptive notes. Head-body 65-90 mm, tail 41-51 mm, hindfoot 14-15 mm. No specific data are available for body weight. Condylo-incisive lengths are 20-7-21-9 mm, and tooth rows are 9-1-10 mm. The Greater Ryukyu White-toothed Shrew is mediumsized. It is a special form characterized by many unique morphological features. Dorsal pelage is light seal brown, and hairs on middle of back are 6-6-5 mm long, much longer than on other species of Crocidura (usually shorter than 5 mm). Ventral pelage gradually changes to light gray. Ears, forefeet, hindfoot, and dorsal surface of tail are brown, and their ventral surfaces are paler. Forefeet are large and wide, and claws are long and robust. Longer bristle hair is distributed on first one-half of tail. Tail is 50-66% of head—body length. Cranial profile is straight. Braincase is short, moderately broad, and rounded. Rostrum is narrow and elongated. Mandible is long, and its ascending ramus is high and broad. I' is slender, with small and narrow posterior cusp (talon). There are three oval-shaped upper unicuspids, parastyle and protocone of upper P* are small, and posterior margin is slightly concave. Lowerincisor is long and broad, and lower molars massive.

Habitat. Only captured in broadleaf natural forests from sea level to elevations of c.300 m. The Greater Ryukyu White-toothed Shrew co-occurs with the Lesser Ryukyu White-toothed Shrew (C. watasei). External morphology indicates it might be able to use semi-fossorial habitat. Okinawa pit vipers (Ouvophis okinavensis) and introduced mongooses are known predators.

Food and Feeding. Coleopterans were found in stomachs of Greater Ryukyu Whitetoothed Shrews.

Breeding. No information.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. Known distribution of the Greater Ryukyu White-toothed Shrew is less than 2500 km? Population is presumably small based roughly on low capture rates, and it might be declining due to reduced natural forests and introduced mongooses.

Bibliography. Correia (2016b), Dubey, Salamin et al. (2008), Imaizumi (1961), Motokawa (1998), Ohdachi et al. (2009).