Sorex unguiculatus Dobson 1890

14.

Long-clawed Shrew

Sorex unguiculatus

French: Musaraigne a longues griffes / German: AmurLangkrallen-Spitzmaus / Spanish: Musarana de unas largas

Taxonomy. Sorex unguiculatus Dobson, 1890,

“ Saghalien Island [= Sakhalin Island]; Nikolajewsk, at the mouth of the Amur River,” Russia.

Evidence from mtDNA and nDNA sequences classifies S. unguiculatus in the caecutiens group. Monotypic.

Distribution. NE China (N Inner Mongolia [= Nei Mongol]), S Russian Far East, S Kuril Is, and N Japan (Hokkaido), including many small offshore islands;it possibly occurs in North Korea.

Descriptive notes. Head-body 70-91 mm,tail 40-55 mm, hindfoot 12-14 mm; weight 6-9-15 g. Pregnant Long-clawed Shrews can weigh more than 17 g. Itis one of the largest species of Sorex. Tail is bicolored and usually longer than 50% of head-body length. Pelage is bicolored. Back varies from brown in juveniles to dark brown in overwintering adults. Dark color of back gradually changes to brown on sides. Belly varies from reddish tinted dark gray in juveniles to intensely gray or grayish brown in overwintering adults. Demarcation between sides and belly colors is indistinct. The Long-clawed Shrew has broad forepaws with well-developed claws up to 5 mm, which are appreciably longer than in other red-toothed shrews. Chromosomal complement has 2n = 42 and FN = 70 on Hokkaido, with 14 pairs of metacentric and submetacentric autosomes and six pairs of acrocentric autosomes, and FN = 68 in the Russian Far East, with 13 pairs of metacentric and submetacentric autosomes and seven pairs of acrocentric autosomes. X-chromosomeis large acrocentric, and Y-chromosome is small acrocentric.

Habitat. Rich broad-leaved and cedar-broad-leaved forests. The Long-clawed Shrew is almost completely distributed in such forests. It is occasionally found in floodplain forests but is absent from forest-steppe habitats. A substantial litter layer is an important habitat component.

Food and Feeding. Earthworms are the main component of the diet of the Longclawed Shrew throughout its distribution. The second most common components are myriapods in Primorsky Krai and mollusks and caterpillars on Hokkaido.

Breeding. Breeding season of the Long-clawed Shrew starts in April (earlier than in other species of Sorex) and usually ends in September in Primorsky Krai and November on Hokkaido. Juveniles start living independently in late May. Females have 2-3 litters/season; up to four litters/season are possible in island populations. Litters have 3-6 young (average 5-2) in Primorsky Krai, 1-9 young (average 5-3) on Kunashir, and 4-8 young (average 5-6) on Hokkaido. Female young-of-the-year rarely reproduce.

Activity patterns. Multiphasic activity by the Long-clawed Shrew is generally low, accounting for ¢.8 hours/day. Peak activity was observed in the beginning and end of the night on Hokkaido and after sunrise in the morning in Primorsky Krai.

Movements, Home range and Social organization..ong-clawed Shrews are rather territorial, just after becoming independent; females are more territorial than males. Home ranges of males are larger than those of females; mean home range of seven resident individuals was 188-3 m®.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Longclawed Shrew often dominates shrew communities and is more abundant than all other coexisting species of shrews combined. It is rather rare at the western periphery of its distribution and is on the Red List in Amur Region.

Bibliography. Churchfield et al. (1999), Grigoriev (1992), Han Sang-Hoon et al. (2000), Hoffmann & Lunde (2008), Inoue (1988, 1991), Nesterenko (1999), Ohdachi (1992, 1994, 1995), Ohdachi & Maekawa (1990), Ohdachi et al. (2009), Okhotina (1974, 1984), Zima et al. (1998).