Sicista strandi
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 strandi

description: 11.
Strand’s Birch Mouse
Sicista strandi
French: Siciste de Strand / German: Strand-Steppenbirkenmaus / Spanish: Ratén listado de Strand
Taxonomy. Sicista montana strand: Formozov, 1931,
Uchkulan, 2100 m, Greater Caucasus, Karachay-Cherkess Republic, Russia.
Northern Species Group. S. I. Ognev in 1948 noted that specimens from lower sections of the Volga and Azov-Black Sea region differed from S. betulina collected near Moscow by their longer tails and grayish dorsum. The two species may also be distinguished by diploid numbers and lengths and shapes of bacula; however, until 1989, strandi was regarded as a population of S. betulina, and based on its distinctive diploid number, the population was referred to as S. betulina “form B” (or karyotype B) or recognized as a separate subspecies. V. E. Sokolov and colleagues in 1989 elevated strand: to species rank, highlighting its distinct karyotype 2n = 44 (compared to that of S. betulina, 2n = 32) and differences in shape and size ofits baculum. Cytochrome-b gene sequence divergence between S. strandi and S. betulina is less than 2%, as documented by T. Cserkész and colleagues in 2016;this is usually indicative of an intraspecific level of divergence and also suggests recent origination/speciation of S. strands. Latest phylogenetic study analyzing cytochrome-b and nuclear interphotoreceptor binding protein (IRBP) gene sequences by Cserkész and colleagues did not uncover significant genetic distance between lowland and montane populations of S. strandi sampled in Lugansk, Ukraine, and North Ossetia, Russia. Western distributional limit of S. strand: verified by karyotype is in the forest steppe zone east of the Lugansk region in Ukraine; historical records of S. strandi west of the Dnieper River near Kiev and otherlocalities have not been confirmed by karyological data, as noted by I. Zagorodnyuk and M. Korobchenko in 2008. Northern distributional limit is ¢.52° N in the vicinity of Lipetsk, and distribution extends eastward from near Kursk and Central Black Earth Nature Reserve to Saratov on west (right) bank of middle Volga River. Northernmost and easternmost karyotyped record of S. strandi was captured near Saratov, west of (right bank of) Volga River, in floodplain of Chardym River, as reported by M. I. Baskevich and M. V. Oparin in 2000. It is unclear if S. strand: occurs on left bank (east of) of Volga River. Monotypic.
Distribution. E Ukraine (LLugansk region) and SW European Russia (regions between Ukraine and Volga River S to N Caucasus).
Descriptive notes. Head—body 65-6-77 mm, tail 85-101-2 mm, ear 9-14 mm, hindfoot 16-19 mm; weight 9-5-13-2 g. Dorsum of Strand’s Birch Mouse is brownish pale yellow in lowland population and brighter reddish and rusty brown in montane population, with conspicuous black mid-dorsal stripe of solid black hairs present in both populations. Venter is white, with pale yellow or rusty tinge. Hindfoot is white and ¢.25% of head-body length. Tail is long, c.130% of head-body length, and usually distinctly bicolored, brown above and whitish below. Condylobasal lengths are 17-7-18-7 mm, zygomatic breadths are 9-7-10-6 mm, interorbital breadths are 3-5-3-9 mm, and lengths of upper tooth rows are 3-2-3-6 mm. Diploid number is 2n = 44. External measurements were obtained from adult males captured in Kabardino-Balkaria and Northern Ossetia by G. I. Shenbrot and colleagues in 1995 and 2008; cranial measurements were from adult males captured in Ciscaucasia and Kabardino-Balkaria, published by the same authors. Diploid number based on individual captured in the Kursk region published by Sokolov and colleagues.
Habitat. Primarily shrub steppe but also meadow steppes, dry ravine forests, and wetter areas such as floodplain forests and meadows, marshes, stream banks, and alder (Alnus; Betulaceae) groves. Habitats are most diverse in the Caucasus, where Strand’s Birch Mouse lives in foothill forest steppe, mountain steppe, subalpine meadows, and subalpine-alpine transition zones up to elevations of ¢.2300 m. Strand’s Birch Mouse seems to be tolerant of periodic burning.
Food and Feeding. Diet of Strand’s Birch Mouse consists of insects, seeds, and vegetative parts of plants. Remains of insects, seeds, and berries were found in stomachs of 20 individuals caught in the Voronezh region by I. I. Barabash-Nikiforov in 1957. In Stavropol, stomachs contained predominantly plant parts and up to 10% insects (Coleoptera, Lepidoptera, and various kinds of caterpillars).
Breeding. In the northern part ofits distribution, breeding of Strand’s Birch Mouse likely commences during the first half ofJune; six adult males and four overwintered females were caught in the Kursk region in the first two weeks ofJune 1983; none of the females were pregnant. Reproductive activity may start earlier in southern part of its distribution; e.g. in Kanevskaya District of Krasnodar territory, a pregnant female with six embryos was caught on 12 May. Barabash-Nikiforov reported that numbers of embryos were 3-5/female in Voronezh region. One litter is produced per year.
Activity patterns. Strand’s Birch Mice are mainly crepuscular and nocturnal, although they are sometimes active during the day in response to low ambient temperatures and/or scarcity of food sources. They hibernate 7-8 months of the year, usually from early October through April. Hibernation may be longer in montane populations, and duration likely depends on climatic factors. S. K. Dahl and Y. D. Chugunov in 1956 noted that in the Stavropol region, the first Strand’s Birch Mouse was caught on 18 April and the last on 2 October. Hibernation in autumn seems to be initiated by mean ambient temperature below 10°C; individuals awaken in spring when mean temperatures reach 10-14°C, according to Dahl and Chugunov.
Movements, Home range and Social organization. Little is known, but Strand’s Birch Mouse is probably solitary, as are most species of Sicista.
Status and Conservation. Classified as Least Concern on The IUCN Red List. Abundance of Strand’s Birch Mice appears low in most years, but capture biases could affect this (e.g. it is possible that pitfall traps have greater capture success). In Ukraine, Strand’s Birch Mice may still be relatively common in some nature reserves in the Streltsovskaya and Provalskaya steppes; unfortunately, military conflicts in eastern Ukraine have resulted in significant damage to these reserves. Outside of these reserves, densities are likely much lower. Strand’s Birch Mice might be common in several large areas of Russia including foothills of the Great Caucasus and steppes in Saratov and Volgograd regions; they are likely less common in densely populated regions of western Russia. The most significant threats to Strand’s Birch Mouse include plowing of virgin steppes, overgrazing, and destruction of ravines. Only significant expansion and restoration of existing protected areas and creating new areas that conserve favorable habitat for Strand’s Birch Mice and other species of small mammals can achieve effective protection.
Bibliography. Barabash-Nikiforov (1957), Baskevich (2016), Baskevich & Okulova (2003), Baskevich & Oparin (2000), Cserkész, Rusin & Sramké (2016), Dahl & Chugunov (1956), Holden & Musser (2005), Ognev (1948), Shenbrot et al. (1995, 2008), Sokolov et al. (1989), Tsvetkova (2008), Tsytsulina et al. (2016), Zagorodnyuk (2005, 2007), Zagorodnyuk & Korobchenko (2008).
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 page 45, DOI: 10.5281/zenodo.6603557