Contents: Volume 16 (1) 2017 (Printed 1 June 2017)

Baryshnikov G.F., Alekseeva E.V.

P. 1-14

Fossil remains of the representatives of genus Mustela from Upper Pleistocene and Holocene levels in Bliznets Cave, located near Nakhodka City, are found to belong to five species: M. erminea, M. sibirica, M. eversmanii, M. altaica, and M. nivalis. Mandibles of M. sibirica may be segregated from those of M. eversmanii on the basis of position of the incision on angular process. All species, except M. eversmanii, currently occur in the southern part of the Russian Far East, while the distribution range of the steppe polecat is shifted to 400–500 km westwards.

Titov V.V., Golovachev M.V.

P. 15-29

A skeleton of a male Mammuthus trogontherii cf. chosaricus is described from Chernyi Yar (Lower Volga Region), the type locality of this subspecies. The skeleton was discovered and excavated from clays of the Singil regional straton in 1996. The geological age of the enclosing sediments is estimated as the terminal Middle Pleistocene and correlated with MIS 7 – MIS 6. The individual age of the animal is estimated as 57–62 years. The calculated shoulder height of the skeleton is 312 cm. Morphological differences from other forms of Mammuthus and Elephas (Palaeoloxodon) are discussed. The distinctions of dental and postcranial characters of M. trogontherii cf. chosaricus, M. trogontherii trogontherii, and M. intermedius are reviewed. A diagnosis of the subspecies M. t. chosaricus is refined.

Lissovsky A.A., McDonough M., Dahal N., Jin Wei, Liu Shaoying, Ruedas L.A.

P. 30-42

We examined 212 complete sequences of the cytochrome b gene for all pika species (Lagomorpha: Ochotona) as well as 250 skulls of pikas from the eastern Himalayan region. The results of our analyses suggest that a new and distinct subspecies of large-eared pika — Ochotona macrotis gomchee ssp.n. occurs in Bhutan. Our phylogenetic analyses indicate that this subspecies holds a sister-taxon relationship to other O. macrotis. The cranial shape of O. m. gomchee ssp.n. is similar to that of remaining O. macrotis; pelage colouration and ear length differentiate O. m. gomchee ssp.n. from all other representatives of O. macrotis. We hypothesize that pikas from the Great Bend of the Tsangpo River, which were previously assigned to O. forresti, in fact belong to O. macrotis; the correct name for that particular subspecies is therefore amended to O. m. duoxionglaensis. The distributional ranges of O. m. gomchee ssp.n. and O. m. duoxionglaensis are hypothesized to be separated by a broad matrix of unsuitable habitats.

Yabe T., Minato R., Hashimoto T.

P. 43-46

We analyzed age distribution of Norway rats (Rattus norvegicus) on uninhabited islands, Yururi (168 ha) and Moyururi (31 ha) in the subarctic climate zone in Hokkaido, Japan. Age was estimated from eye lens weight. From the age distribution of 73 rats caught in July–August 2013, we found that 10 rats of them were born under the snow cover from December to March.

Gromov V.S.

P. 47-65

Sociality means group-living. Among rodents, the most social species live in family groups that consist as a rule of not numerous individuals. Hence, the evolution of sociality among rodents is not a group-size evolution. A family-group lifestyle is associated with long-lasting pair bonds, participation of both parents in care of young, and cooperation in different activities. In family groups, cooperation starts from the very beginning when a breeding pair establishes, protects and marks its home range, digs burrows or constructs other shelters, and provides care-giving activities. Direct parental care (especially paternal care) by means of tactile stimulation of the young is suggested to promote long-lasting pair bonds and development of subsequent parental behaviors in sub-adult and adult males that is so typical of highly social rodent species. This phenomenon has an epigenetic nature and could be considered as ‘stimulation of similar with the similar’. Cooperation extends and intensifies when the size of family groups increases as a result of delayed dispersal of the offspring. According to the proposed conceptual model, family groups could be formed under any ecological conditions, irrespective of predation pressure or resource distribution, given that mating pairs and, furthermore, family groups are more competitive due to cooperation than solitary conspecifics. The main driving forces are proximate mechanisms related to tactile stimulation of young individuals during their early postnatal development and cooperation. This conceptual model provides a better understanding of the evolution of sociality (i.e. transition to a family-group lifestyle) in different rodent taxa.

Orlova M.V., Kazakov D.V., Orlov O.L., Mishchenko V.A., Zhigalin A.V.

P. 66-73

This article presents one of the very few records of a macronyssid mite (Mesostigmata, Gamasina, Macronyssidae) infestation of vesper bats (Chiroptera, Vespertilionidae). It is the first report of the influence of host parameters on the infestation of the parti-coloured bat, Vespertilio murinus, by the mite Steatonyssus spinosus. It has been shown that the infestation varies considerably throughout the host’s occupation of summer roosts and the highest infestation was observed in the post-lactation period. Female bats are infested significantly more intensively than male bats due to changes in their immune status during pregnancy and lactation. The infestation decreases in the period when the breeding colony disbands due to both roost switching and the intensification of grooming during this period.

Zakharov E.S., Safronov V.M.

P. 74-85

In 2003–2012, 687 carcasses of aboriginal sables of Zhigansk population represented by the Yenisey subspecies (Martes zibellina yeniseensis Ognev, 1925) inhabiting North-Western Yakutia were studied. Skull and body size of native sables were larger and fur colour was lighter as compared to the Vitim subspecies (M. z. princeps Birula, 1922) introduced in South-Western Yakutia (Olekma population). Dynamics of the native population is characterized by the prevalence of natural cycles at moderate hunting rates. The portion of juveniles made up 69.3% on average. Among adults 37.0% were 1-year-old animals, 25.1% 2-year-old, and 13.3% 3-year-old sables. Animals aged 4 to 12 years were less numerous (24.6%), especially females (8.5%). Fertility (3.46±0.2) and fecundity (2.77±0.3) rates as well as the number of reproducing females (61.4%), especially at the age of one year (2.9%), were less than in Olekma population. The diet of Zhigansk sables was based on northern red-backed voles (Myodes rutilus) (43.7% of studied stomachs), grey red-backed voles (Craseomys rufocanus) (43.7%) and root voles (Alexandromys oeconomus) (50.2%). Consumption of pikas (Ochotona sp.) was increased (up to 31.2%) in separate years. Birds were rarely consumed (1.6%). Plant food mainly consisted of bog bilberry (Vaccinium uliginosum) (15.5%). Poorly-nourished sables made up 71.9% of the sample. The number of moderately fat and very fat sables increased with age. Among them, males (30.2%) prevailed over females (25.7%). The relative mass of paranephric fat was lowest in sables aged 1 to 8 years. Sex-related differences in fat index were recorded only in juveniles.

Bobretsov A.V., Lukyanova L.E.

P. 86-93

The paper presents the results of the monitoring (1988–2016) of wood lemming Myopus schisticolor (Lilljeborg, 1844) numbers from different landscape areas of the Pechora-Ilych Nature Reserve. It is shown that the population dynamics of this species differ considerably between marked landscapes. The lowland area is characterized by low number of animals with a rare irregular increase of abundance. The cyclic fluctuations were revealed in the foothills with a period of 3–4 years. In the years of depression the abundance indices dropped to zero and quite often it exceed over 100 individuals per 100 cone/nights in the years of number outbreaks. The migrations of animals are observed during the periods of high density. In the lowlands the wood lemming is marked only the next year after a sharp increase in its numbers in the foothills.

Kovalyov D.N.

P. 94-109

Myotis bats were investigated from all known artificial caves of Leningrad Region. The bat’s wintering places (hibernaculi) studied during eight seasons from 2007 to 2015 within a long-term bat monitoring effort. The following mouse-eared bat species were found: Myotis dasycneme (Boie, 1825) — pond myotis, M. daubentonii (Kuhl, 1817) — Daubenton’s myotis, M. nattereri (Kuhl, 1817) — Natterer’s myotis, and species complex Myotis brandtii/mystacinus — Brandt’s/whiskered myotis. Massive hibernacula of the Natterer’s myotis, Brandt’s/whiskered myotis, and pond myotis was found within group of Staroladozhskije Caves; namely, Tanechkina Cave at present is a biggest known simultaneously wintering of Myotis bats. Hibernaculi and theirs vicinity microclimatic conditions were described with using instrumental measurements of the temperature and humidity. The specific preferences of the studied species were identified that connected with position of hibernating groups relative cave entrances and underground water capacity, specific micro-conditions of temperature and humidity ranging. As result, we have a preliminary assessment of the relationship between the size of the hibernacula and the well-being of the mouse-eared bat populations from territory of Leningrad Region. In addition, we attempted to assessment of a vulnerability of the some hibernating colonies, and, in general, populations of the several studied species.

Kryukova N.V.

P. 110-113

Three cases of concrescence of the fourth premolar with the first molar and one case of concrescence of the third and the fourth premolars are described in the Pacific walrus, Odobenus rosmarus divergens (Illiger, 1815). These cases represent 0.3% of the total number of inspected teeth (n = 1206) from 307 animals. All individuals (n = 3) were adult males aged 22–26 years old. The beginning of concrescence was found in animals ranging from 7 to 23 years old. The sections of concrescent teeth showed them to be joined by newly deposited layers of cementum.