563.

Ryukyu Mouse

Mus caroli

French: Souris de Rothschild / German: Reisfeldmaus / Spanish: Raton de Ryukyu

Other common names: Ricefield Mouse

Taxonomy. Mus caroli Bonhote, 1902,

“Okinawa [Island], Liu-Kin [= Ryukyu] Islands,”

Japan.

Placed in subgenus Mus by J. T. Marshall

in 1977; according to a 2010 molecular phylogeny of T. Shimada andcolleagues, it belongs to a clade that also includes M. cooku and M. cervicolor . The species seems to present a high morphological variability acrossits range. Monotypic.

Distribution. S China (Yunnan, Guizhou,

Guangxi, Guangdong, Fujian, and Hainan), Taiwan, Vietnam, Laos, Cambodia, S Myanmar, and Thailand; also present in Peninsular Malaysia, Sumatra and adjacent Is, E Java and adjacent Madura I, and Japan (Okinawa I), but origin is uncertain. Introduced to Flores I, Indonesia.

Descriptive notes. Head—body 62-95mm,tail 65-95 mm, ear 12-14 mm, hindfoot 15-19 mm; weight 11-5-19-5 g. This medium-sized mouse has grayish-brown dorsal pelage, with stiff fur, and gray-white ventral pelage. Tail is about the same length as head-body length. On the skull, incisors project forwards (proodont) and nasal bone is short.

Habitat. Pine grass savanna or grass patches in deciduous forests of Thailand. The Ryukyu Mouse is common in rice fields and secondary forest.

Food and Feeding. Diet consists of plant matter and insects.

Breeding. In captivity, females may raise litters of 5-6 young in a round nest made of grass.

Activity patterns. Ryukyu Mice are terrestrial and primarily nocturnal. Some individuals are seen out of the burrows during the day.

Movements, Home range and Social organization. The Ryukyu Mouse digs burrows with two entrances leading to a chamber. Burrow entrances are opened at night and signaled by small mounds offreshly excavated soil.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Lekagul & McNeely (1977), Marshall (1977a), Musser & Carleton (2005), Shimada et al. (2010), Smith & Yan Xie (2008).