Sicista caudata Thomas 1907
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
name: Thomas E. Lacher, Jr
Publisher: name: Lynx Edicions
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Dipodidae
Sicista
Sicista caudata

description: 1.
Long-tailed Birch Mouse
Sicista caudata
French: Siciste a longue queue / German: Langschwanzbirkenmaus / Spanish: Ratén listado de cola larga
Taxonomy. Sicista caudata Thomas, 1907,
17 miles NW Korsakov, Sakhalin Island, Sakhalin Oblast, Russia.
Eastern Montane Species Group. Sicista caudata is closely related to S. tianshanica and S. concolor. B. S. Vinogradov in 1937, J. R. Ellerman in 1940, and Ellerman and T. C. S. Morrison-Scott in 1951 believed that some features exhibited by S. caudata and others in this species group, such as a relatively long hindfoot and tail, aligned with S. caucasica, now in the Western Montane Species Group. Vinogradov and Ellerman concluded that monochromatic eastern montane species and monochromatic S. caucasica formed a natural group distinct from the only other unicolored species known at that time, S. napaea, now in the Northern Species Group. Geographical variation among all populations of S. caudata has not been fully evaluated, but G. I. Shenbrot and colleagues in 1995 and 2008 observed no differences in fur color, morphology of male genitalia, or karyotype between the mainland Pacific coast population and Sakhalin Island population. Monotypic.
Distribution. Russian Far East in Sakhalin I, Sikhote-Alin Mts, and Ussuri River Basin, and along Pacific coast in Khabarovsk and Primorsky krais (including Russkiy I in Peter the Great Gulf), NE China (Heilongjiang and Jilin), and N Korea (N Ryanggang and NW South Hamgyong).
Descriptive notes. Head-body 66:8-76-9 mm, tail 99-4-118-2 mm, ear 10-13-8 mm, hindfoot 16-7-18-8 mm; weight 8-1-16-3 g. Dorsum of the Long-tailed Birch Mouse is yellowish gray tinged with brown, overlaid with dark tips and guard hairs over back and yellowish along sides of body. Venteris yellowish white. Hindfoot is ¢.25-26% of head-body length. Tail is more than ¢.160% of head-body length and unicolored yellowish or brownish gray. Condylobasal lengths are 17-2-18 mm, zygomatic breadths are 9-4-10-1 mm, interorbital breadths are 4-1-4-2 mm, and lengths of upper tooth rows are 2-7-3 mm. Diploid number is 2n = 50. External and cranial measurements of adult males and females from southern Sakhalin Island were reported by Shenbrot and colleagues in 1995 and 2008; diploid number reported by same authors and is based on a single individual captured in Primorsky Krai.
Habitat. Conifer and broadleaf forests, including ecotones associated with them, and stream banks and other riparian habitats. The Long-tailed Birch Mouse primarily occurs in forests but also uses clearings covered with tall grass and forbs in forest ecotones and vegetated floodplains. Habitat information comes primarily from collection localities in Russia. In northern Sakhalin Island, Long-tailed Birch Mice inhabit most natural forests except larch (Larix, Pinaceae) forest according to V. G. Krivosheev in 1984 and Shenbrot and colleagues. On most of the island, old growth forests offir (Abies) and spruce (Picea), both Pinaceae, seem to be preferred habitat, and at the southern end, conifer and mixed broadleaf forests are occupied. Individuals have been captured on Sakhalin Island in ecotones and disturbed areas such as reed grass stands, birch (Betula, Betulaceae) groves with shrubby understory, bamboo groves, and montane river floodplains with tall grass and sparse trees. In the Sikhote-Alin Mountains, Long-tailed Birch Mice occur in conifer-broadleaf forest at low elevations up to coniferous montane forest at higher elevations. In North Korea, they have been frequently recorded along stream banks in mountain valleys and moist meadows, marshes, and other habitats with dense grasses and sedges.
Food and Feeding. Wild Long-tailed Birch Mice primarily eat seeds but also adult and larval insects, flowers, parts of green plants, and fruit, as noted by Krivosheev in 1984 and Shenbrot and colleagues in 1995 and 2008. Captive individuals ate oily seeds from spruce, sunflower (Asteraceae), walnut (Juglans, Juglandaceae), and cedar (Cupressaceae) and readily ate beetle and lepidopteran larvae, other insects, raisins, berries, and other ripe fruits. Shenbrot and colleagues speculated that diets in the wild likely change seasonally, consisting primarily of insects and tender green plant parts that provide protein and vitamins in spring and early summer when mice arise from hibernation and become reproductively active; seeds, high in carbohydrates and fat, are likely main diet components in autumn when hibernation approaches.
Breeding. [Long-tailed Birch Mice have onelitter per year, as indicated by decrease of testes size in autumn and changes in the female reproductive system. Litters contain 2-8 young. Shenbrot and colleagues captured young that had apparently just left the nest in late August to early September on Sakhalin Island; young-of-the-year appear to breed only in the following breeding season.
Activity patterns. [Long-tailed Birch Mice are crepuscular and nocturnal but generally inactive during the middle of the night. Like other species of Sicista, they hibernate in winter, but when hibernation begins and ends is unknown. Thereis little information regarding their burrows and nests, but old decaying stumps in coniferous forests are used for daily shelter and winter hibernation.
Movements, Home range and Social organization. Captive Long-tailed Birch Mice are extremely timid, similar to other species of Sicista.
Status and Conservation. Classified as Data Deficient on The IUCN Red List. Despite insufficient data on population trends and potential conservation threats, the Longtailed Birch Mice is considered naturally rare and patchily distributed in the Russian part of its distribution. In North Korea, it is also rare but has been recorded to be abundant in certain areas, such as Bujeon-gun in South Hamgyong Province. Because it 1s tightly associated with old-growth coniferous forests in the Russian Far East,it becomes increasingly rare with removal of primary forests and their replacement by second-growth formations. Long-tailed Birch Mice occur in some protected areas such as Kedrovaya Pad and Botchinskii nature reserves.
Bibliography. Baskevich (2016), Clayton (2016a), Ellerman (1940), Ellerman & Morrison-Scott (1951), Gromov & Erbajeva (1995), Holden & Musser (2005), Jiang Zhigang etal. (2015), Kostenko (1984), Krivosheev (1984), Reimers et al. (1968), Shenbrot et al. (1995, 2008), Sheremetev (2004), Smith (2008a), Smith & Yan Xie (2013), Sokolov & Kovalskaya (1990b), Vinogradov (1937), Wang Yingxiang (2003), Won Changman & Smith (1999), Won Hong-Gu (1968).
description: Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Sminthidae, pp. 9-48 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on pages 38-39, DOI: 10.5281/zenodo.6603557