Azumi Shrew

Sorex hosonoi

French: Musaraigne d'Hosono / German: Azumi-Spitzmaus / Spanish: Musarana de Azumi

Taxonomy. Sorex hosonoi Imaizumi, 1954,

foot of Mt. Gaki, ¢. 900 m, Maneki, Kitaazumi District, Tokiwa village, Nagano Prefecture, Central Honshu, Japan.

Sorex hosonoi 1s sister to S. minutissimus based on molecular studies. It used to include subspecies shiroumanus based on a single specimen that was from the same district, but hardly any difference can be observed between the two forms. Monotypic.

Distribution. Restricted to middle and high mountains in C Honshu, Japan.

Descriptive notes. Head-body c.54-6-58-3 mm, tail 42-55-5 mm, hindfoot 10-5-12:5 mm; weight 2-7-5-5 g. Condylo-incisive length averages 16-3 mm, and tooth row averages 6-5 mm. The Azumi Shrew is similar to the Shinto Shrew ( S. shinto) but smaller and characterized by relatively longer tail. Chromosomal complement has 2n = 42 and FNa = 66.

Habitat. Grasslands, shrublands, and coniferous forests in subalpine to alpine zone at elevations of 900-3000 m. The Azumi Shrew is rarely found at low elevations. It is more common at microhabitats near rocky streams and waterfalls.

Food and Feeding. No information.

Breeding. Breeding season of the Azumi Shrew on Mt Hakusan, Ishikawa Prefecture, occurs in July-September. Up to six embryos have been reported.

Activity patterns. Azumi Shrews are terrestrial, being well adapted for running and also good atjumping and climbing. In captivity, they have been observed sleeping on a 10cm high branch. Most individuals were captured at twilight and night.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Although the Azumi Shrew has a limited distribution, most of its natural habitats are well protected. It is syntopically distributed with, but less common than, the Shinto Shrew; competition does not seem to be a threat to natural populations.

Bibliography. Abe (1967), Imaizumi (1954), Ohdachi et al. (2009).