Sicista pseudonapaea Strautman 1949
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 pseudonapaea

description: 9.
Gray Birch Mouse
Sicista pseudonapaea
French: Siciste grise / German: Sudliche Altai-Birkenmaus / Spanish: Ratén listado gris
Taxonomy. Sicista pseudonapaea Strautman, 1949,
E Kazakhstan, S Altai Mtns, N slope of Narymskiy Range, Katon-Karagay.
Northern Species Group. B. S. Vinogradov and I. M. Gromov in 1952 and Gromov and colleagues in 1963 referred to this taxon as a subspecies of S. betulina, despite significant differences between them in fur color,tail length, and structure of male genitalia. V. E. Flint and colleagues in 1970 noted that some researchers considered the taxon from the southern Altai a separate species, S. pseudonapaea. Unicolored S. pseudonapaea and S. strandi have the same diploid number (2n = 44) and numbers of arms, but karyotypes differ in shapes of two pairs of biarmed chromosomes. The karyotypes of S. napaeais also similar, with its diploid number differing only by two (2n = 42), but these two species differ in size of keratin spikes on glans penis. In a phylogenetic study using DNA sequences by T. Cserkész and colleagues in 2017, significant genetic divergence was detected between S. napaea and S. pseudonapaea. These two species lacking mid-dorsalstripes, are genetically close to S. betulina and S. strandi, which have mid-dorsal stripes. M. I. Baskevich and N. M. Okulova in 2003 provided a key based on skull measurements useful for identifying species in the Northern Species Group, which includes S. pseudonapaea. Steppe zone of southern Altai in east Kazakhstan defines western distributional limit of S. pseudonapaea; eastern boundary is unknown. Swcista pseudonapaea might occur in northern Xinjiang, China, based on a genetic sequence originally identified as S. concolor. A. A. Sludskiy and colleagues in 1977 noted that Kurchum River Valley defines southern distributional limit, but S. pseudonapaea possibly occurs across Kurchum River in mountains along Lake Markakol. Monotypic.
Distribution. S Altai on the N & S slopes of the Narymsk Ridge between the Bukhtarma River and Lake Markakol (E Kazakhstan); it may also occur in adjacent N Xinjiang (NW China).
Descriptive notes. Head-body 65-77 mm, tail 82-102 mm, hindfoot 12-18 mm, ear 12-17 mm; weight 10-13-3 g. Dorsum of the Gray Birch Mouse is gray or brownish gray, with conspicuous black guard hairs and no mid-dorsal stripe. Venter is grayish white. Sides of body and cheeks appear paler and brighter due to absence of black-tipped guard hairs. Hindfoot is ¢.25% of head-body length. Tail is short compared with other species of Sicista, ¢.130% of head-body length, and together with dorsal color, aids in identification of the Gray Birch Mouse. Tail is bicolored, brownish gray above and whitish gray below. Condylobasal lengths are 18:6-19-5 mm, zygomatic breadths are 9-6-10-5 mm, interorbital breadths are 3-8—4-2 mm, and lengths of upper tooth rows are 3-1-3-5 mm. Diploid number is 2n = 44. External and cranial measurements were taken from adult males captured from south-eastern Kazakhstan, published by G. I. Shenbrot and colleagues in 1995 and 2008.
Habitat. High grass meadows with thickets of wild rose (Rosaceae), barberry (Berberis, Berberidaceae), and currant (Ribes, Grossulariaceae); sparse park-like larch (Larix, Pinaceae) forests; and patches of steppe on upper terraces of the Sarymsakty River overgrown with feather grass (Stipa) and fescue (Festuca), both Poaceae, and patches of white wormwood (Artemisia, Asteraceae) at elevations of 1000-2200 m. The Gray Birch Mouse is most common in habitats that offer shrub cover, shelter, and variety of preferred insect prey and plants.
Food and Feeding. Diet of Gray Birch Mice consists of green parts of plants, seeds, rhizomes, and insects. Remains of elytra from small beetles were found in two of 19 stomach and intestine contents examined.
Breeding. Breeding season of the Gray Birch Mouse likely commences in May and continues through at least mid-July. Females have one litter per year, and repeated pregnancies have never been noted in the same breeding season. By mid-June, all adult males have well-developed testes and sperm in epididymides. Sludskiy and colleagues found three pregnant females, each carrying four embryos, in late June and earlyJuly. Life span in the wild is likely c.2 years. G. A. Klevezal in 2002 analyzed a sample of 33 individuals collected in the Altai Mountains in June, and only 1% of them had survived more than two winters.
Activity patterns. The Gray Birch Mouse is crepuscular and nocturnal. When checking pitfall traps in the morning, many individuals were found inactive and, in some cases torpid, a common response by birch mice to low temperatures even in summer. The Gray Birch Mouse hibernates in winter, but starting dates and durations have not been established.
Movements, Home range and Social organization. Gray Birch Mice are agile and move with small jumps. They apparently do not migrate seasonally or form colonies. They shelter in burrows of other rodents and spaces among stones and tree roots.
Status and Conservation. Classified as Data Deficient on The IUCN Red List. The Gray Birch Mouse has only a few positively identified records from a small number of localities, and its habitat is threatened by overgrazing and loss of tall grass and herbaceous cover in agricultural areas. It is endemic to the southern Altai, but nothing is known about the population in China; more data are needed to adequately assessits conservation status. It can be common in optimal, relatively undisturbed habitats. In Kazakhstan,its protection is ensured in Markakol Nature Reserve and Katon-Karagay National Park. Its distribution may be smaller than 20,000 km?, and area of occupancy is estimated to be ¢.2000 km®. Presumably, overall population is not declining or fluctuating substantially so classification as Least Concern is suggested.
Bibliography. Baskevich (2016), Baskevich & Okulova (2003), Clayton (2016b), Cserkész, Filop et al. (2017), Flint et al. (1965), Gromov & Erbajeva (1995), Gromov et al. (1963), Klevezal (2002), Pavlinov & Lissovsky (2012), Shenbrot et al. (1995, 2008), Sludskiy et al. (1977), Sokolov & Kovalskaya (1990a, 1990b), Sokolov et al. (1982), Vinogradov & Gromov (1952, 1984).
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 43-44, DOI: 10.5281/zenodo.6603557