Sorex gracillimus Thomas 1907
Creators: name: Mittermeier, Russell A.
name: Wilson, Don E.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Soricidae
Sorex
Sorex gracillimus

description: 10. Slender Shrew <i>Sorex gracillimus</i> <b>French:</b> Musaraigne gracile / <b>German:</b> Schlanke Spitzmaus / <b>Spanish:</b> Musarana esbelta <b>Taxonomy.</b> Sorex minutus gracillimus Thomas, 1907, “ Dariné, 25 miles [= 40 km] N.W. Korsakoff [= Korsakov], Saghalien [= Sakhalin Island],” Russia. Evidence from mtDNA and nDNA sequences classifies S. gracillimus in the S. minutissimus group, although this group may be better included under the S. minutus group; further studies of all Sorex taxa are needed. Three subspecies recognized. <b>Subspecies and Distribution.</b> S.g.gracillimusThomas,1907—SakhalinandKunashirIs. S.g.grantiOkhotina,1991—SKurilIs(HabomaiandShikotan). S. g. minor Okhotina, 1991 — Russian Far East (from S Magadan S to Primorsky Krai), NE China, and North Korea. Also present on Hokkaido and many small offshore islands, N Japan, but subspecies involved not known. <b>Descriptive notes.</b> Head—body 45-66 mm (immatures 45-52 mm), tail 36-49 mm, hindfoot 10-11 mm; weight 2-5-5-3 g (immatures 2-5-3-8 g). Tail of the Slender Shrew is usually longer than 75% of head-body length. Pelage is bicolored. Back varies from light brown in juveniles to dark brown in adults. Sides are slightly lighter than back. Belly is silver-gray to gray. In juveniles, dark back gradually changes to the lighter color of sides and belly, and light color of belly extends onto sides. In adults, contrast between back and belly colors is greater. Tail is sharply bicolored; tuft at tip oftail is dark. Chromosomal complement has 2n = 36 and FN = 62, with 13 pairs of metacentric autosomes and four pairs of acrocentric autosomes. X-chromosome and Y-chromosome are acrocentric. <b>Habitat.</b> Various habitats. Floodplain biotopes are exclusively occupied in the Sea of Okhotsk region in northern part of the distribution, old riverside larch stands being the most preferred. Young small-leaved forests are preferred on southern Sakhalin, and old dark coniferous forests and anthropogenic meadows and fields are avoided. Coniferous broadleaved forests on lower slopes of mountains are preferred in Primorsky Krai, and open regions of the forest-steppe zone are avoided. The Slender Shrew is more often found in bamboo groves and forb meadows on Kunashir and Shikotan islands. In Hokkaido, it occurs in many habitat types but is more dominant in wetlands and higher places. <b>Food and Feeding.</b> Spiders and myriapods predominate in the diet of Slender Shrews in southern Primorsky Krai. Those two groups, caterpillars, harvestmen, and adult beetles predominate in diets on Hokkaido. Earthworms were almost never found in diets of Slender Shrews. Proportions of seeds in diets increase in autumn. <b>Breeding.</b> Breeding season of the Slender Shrew occurs in April-October or even November on Hokkaido; females produce two litters/season, rarely three. Young-of-theyear rarely reproduce, as findings from a major part of Primorsky Krai and Hokkaido confirmed. Only two captures of pregnant young-of-the-year were reported from Zeya (Amur Region) and Lazovsky (Primorsky Krai) nature reserves. Numbers of embryos/ female are 1-8, and mean numbers of embryos are very similar in different geographical localities (e.g. 5-6 on Sakhalin and 5-8 on Hokkaido). <b>Activity patterns.</b> Activity of the Slender Shrew is basically nocturnal, with two peaks of higher activity after sunset and before sunrise. The Slender Shrew is terrestrial and moves mostly on the ground’s surface. It can dig soil but does not construct a tunnel system byitself. <b>Movements, Home range and Social organization.</b> Average home range of the Slender Shrew is 259-4 m? on northern Hokkaido. Slender Shrews are solitary. <b>Status and Conservation.</b> Classified as Least Concern on The IUCN Red List. The Slender Shrew is common but often subdominant in the shrew community, being the second or third most abundant; it is rarely dominant. Abundance of the Slender Shrew decreases at the periphery of its distribution, and it becomes rare, being therefore on Regional Red Lists in Amur and Magadan regions. <b>Bibliography.</b> Andreev et al. (2006), Churchfield et al. (1999), Nesterenko (1999), Ohdachi (1992, 1994, 1995), Ohdachi &amp; Maekawa (1990), Okhotina (1974, 1991), Reimers &amp; Voronov (1970), Zima et al. (1998).
description: Published as part of <i>Russell A. Mittermeier &amp; Don E. Wilson, 2018, Soricidae, pp. 332-551 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions</i> on page 398, DOI: 10.5281/zenodo.6870843