The body temperature dynamics of the Ciscaucasian hamster (Mesocricetus raddei) during winter hibernation was studied in semi-natural conditions (a mesh cage buried in the ground, where animals could dig burrows) in mountainous Dagestan. Thermologgers were implanted intraperitoneally to seven adult animals (three females and four males) to record body temperature at 30 min intervals. All individuals successfully overwintered and exhibited regular episodes of hypothermia. The average of total duration of one heterothermia period was 192±6.8 days, that of one hypothermia and normothermia episode was 15 5.3±6.2 h and 16.5±1.2 h, respectively. The minimum body temperature reached +0.5°C. It has been shown that the body temperature and the duration of hypothermia episodes are negatively correlated with the temperature inside the burrow. Adaptive hibernation mechanisms of the Ciscaucasian hamster and other hibernating mammalian species are discussed.

In the conditions of the Northwestern Caspian Sea, the state of the midday sand lance population is determined by the dynamics of food resources. An important component of the environment that determines the condition of the midday gerbil is bush thickets, which serve as good shelter for the animals. It has been established that on a sand dune where a higher density of shrubs is noted, compared to open areas of the deserted steppe, the productivity of vegetation increases and the species composition of plants changes. The relationship between the gerbil population density and vegetation productivity was shown (R = 0.74, P < 0.05). In addition, the relationship between the number of gerbils and the productivity of bluegrass bulbs (Poa bulbosa) is shown, which fluctuated during the years of research in the sand dune area from 3.7 to 5.5 dt/ha of dry weight, and in the desert steppe area from 2.3 to 3.8 dt/ha. In accordance with the nature of the provision of food resources, changes in the number of midday gerbils were noted in different seasons of the year from four to 24 individuals/ha on sand dunes and from two to 14 individuals/ha in the desert steppe.

In 2015–2018, a study was made of the species composition, productivity of the vegetation cover and the composition of the diet of midday gerbil in the arid zone of the Northwestern Caspian Sea region. Midday gerbils use all types of available food in their diet, but the food can vary significantly in percentage in different seasons of the year. Using the method of cuticular–scatological analysis, it was shown that in the spring the largest share in the diet of gerbils is made up by Lapulla squarrosa (K = 15.97), Hordéum vulgáre (K = 9.5), and Medicago sativa (K = 5.4) and in summer by Poa bulbosa (K = 12.3), Amaranthus albus (K = 3.5), and Agropyron sibiricum (K = 4.3). In autumn, high rates of selectivity are characteristic of Poa bulbosa (K = 13.2). In winter, midday gerbils feed mainly on the seeds of Amaranthus albus (K = 11.2) and Agropyron sibiricum (K = 2.5), as well as Poa bulbosa (K = 14.3). In winter, there is almost no selectivity in the diet of midday gerbils and they use all the food available at this time of the year. Basically, the diet of the gerbil is made up by xerophytic vegetation species.

Studies on the age characteristics of the quantitative and qualitative aspects of nutrition and energy of the Midday gerbil in captivity showed that the consumption of various types of food ranges from 4.2 to 7.5 g of dry matter per individual per day, depending on the age of the animals and the quality of the feed offered. The absolute dry matter intake reaches the maximum at air humidity levels close to 50–55%. The absolute values of food consumption by adult animals are 1.3–1.5 times higher than those of young ones. The relative level (per 10 g of body weight) of feed intake is 1.1–1.3 times, and the relative energy requirements are 1.2–1.5 times higher in young animals than in adults. Considering that the relative energy requirements of young gerbils are higher, while the absolute values of their nutrition are lower than those of adults, they need more nutritious feeds in comparison with adults to ensure an energy balance. Consequently, in nature, young animals should be more demanding for food quality, and therefore any changes in the quantity and quality of food resources will primarily affect the condition and survival of young individuals.

In 2015-2017, the study of the ration of tamarisk gerbil in the arid zone of the North-Western Precaspian, which use almost the entire available range of growing plant species in nutrition, was carried out. However, in each season, only a small number of plant species formed the basis of nutrition. The availability of feed resources of tamarisk gerbils in all seasons of the year is achieved both due to the natural change of vegetating plant species and due to the change of the type of feed resource (green parts of plants, bulbs, seeds, fruits and insects).

As part of the inventory work in the Kosobsko-Keleb Reserve in 2017–2019, the species composition was identified and the relative abundance of rodents on the south-eastern slope of the Bogos ridge was estimated. It is shown that rodents inhabit a fairly wide range of biotopes on the south-eastern slope of the Bogos ridge, which is largely predetermined by the peculiarities of their ecology and the nature of their specialization.

The teeth of an adult female of the Turkish hamster (Mesocricetus brandti) after hibernation in semi-natural conditions were examined to reveal a relationship between the hibernation pattern on the incisor surface and the data of a temperature logger. The female spent the winter in a burrow prepared by herself inside a wintering cage from October 2018 till May 2019. A temperature logger was implanted to the animal intraperitoneally to record body temperature at 20-min intervals. Regular bouts of hypothermia started in mid-October. The longevity of each hypothermia bout increased whereas the minimum body temperature decreased and reached its lowest value in March. Later, the process proceeded backwards until the end of the heterothermia period. In the apical region of the incisor, daily increments were wide and well-distinguished which indicates that they had formed before the onset of the heterothermal period. In the basal region, closer to the growth zone, the increments were narrow and distinct, and their number corresponded in general to the number of normothermia episodes bouts. At the very base of the incisor as well as at its apical part, typical daily increments were revealed again. However, no correlation between the longevity of normothermia bouts and the width of increments was found. These data varied greatly from two other hamsters. In the Ciscaucasian hamster (Mesocricetus raddei) the number and character of increments comply with the number and duration of normothermia bouts, in the Common hamster (Cricetus cricetus), the “hibernation zone” was not recorded on the incisor surface. The Turkish hamster demonstrate an intermediate pattern, which we explain by quite different hibernation conditions of these species.

As part of the inventory work in the kosobsko-keleb Reserve in 2017–2019, the species diversity of shrews in the Kosobsko-Keleb Reserve was revealed. For the first time on the territory of the reserve found Sorex raddei, Sorex caucasica, Neomys teres. Estimates of the abundance of Sorex volnuchini, Crocidura suaveolens, and Crocidura leucodon are given.

The summer daily activity of the Radde hamster was studied using radio telemetry and the FAIS system. It is shown that the daily activity of the Radde hamster varies significantly from May to August for both males and females, which is associated with different tasks solved by hamsters in each month. Due to the behavior of the Radde hamster, the radio telemetry method does not allow us to get a reliable picture of daily activity.

For the last 25 years the structure of the agriculture in Mountainous Daghestan was cardinally changed - the area of crops has decreased by 3 times, and the crops of grain crops have been replaced by vegetables. These changes were directly reflected on the state of the population of the hamsters Mesocricetus raddei and M. brandti. The range of these species has become fragmented, and their number grew shorter. The change in land use conditions signifi-cantly affected the nature of the use of the territory and the diurnal surface activity of the Ciscaucasian hamster.

The article presents data on the nature of reproduction of the midday gerbil in the North-Western Precaspiansea. It is shown that the intensity of reproduction of the midday gerbil reveals a relationship with two factors: the level of fodder resources during the beginning of reproduction and the intensity of their nutrition during this period.

Abstract—The lower incisors of ten hamsters from the Khunzakh region of Dagestan were studied. One hamster implanted with a temperature data logger successfully survived one winter in natural conditions, and its body temperature curve revealed 25 episodes of hypothermia with the body temperature dropping to 1–9°C, i.e., the period of hibernation. On the surface of the incisors, against a background of very indistinct increments, a zone with more distinct increments was observed. From the apical part of the zone to its basal part, the width of these increments decreased to very narrow, almost indistinguishable increments, and then increased. A comparison of the number of increments formed after this zone with the number of days the hamster survived after arousal from hibernation indicated that the zone was formed during hibernation. The pattern of variation in the increment width in the “zone of hibernation” corresponded to that observed in the episodes of normothermia during hibernation. A similar “zone of hibernation” was seen on the incisor surface in six of nine specimens caught in the field in June to early July. The date of their arousal was calculated from the number of increments corresponded to the date of arousal of the hamsters in this region, according to field observations. The pattern of the hibernation record on the incisors of these hamsters was mainly similar to that in the hamster with the temperature data logger and also demonstrated individual variations. Due to the poor contrast of increments on the incisor surface of these hamsters, it is difficult to use this record of hibernation for precise calculation of the data of arousal or for estimation of the duration of every episode of normothermia during hibernation. However, it is possible among the animals caught in spring to early summer to distinguish specimens aroused earlier or later using the position of the “zone of hibernation” on the incisor. It is also possible to estimate the relative duration of periods with short or long episodes of normothermia using the ratio of fragments with different widths of the increment in the “zone of hibernation.”

The responses of populations and communities of small mammals have been studied under different grazing regimens. It is shown that overgrazing and grazing restriction can have a considerable impact on the population status, demographic structure, and alspecies composition of small mammals in the Caspian northwest coast area (Nogai Steppe) and the steppes of Eastern Mongolia

Monitoring daily activity patterns of animals in the field and in captivity often revealed different results. For example, Syrian hamsters Mesocricetus auratus showed diurnal surface activity in the field, but noc-turnal patterns in the laboratory. The aim of our study was to monitor the field activity of a close relative of this species, the Ciscaucasian hamster Mesocricetus raddei from Dagestan. Using the radio-frequency identification (RFID) technique we were able to obtain field data from 20 Ciscaucasian hamsters. In con-trast to the data obtained in captivity where the Ciscaucasian hamsters were active mainly at night, they showed a diurnal activity pattern in the field, i.e. animals were observed on surface between sunrise and sunset. Discussing the putative causes of the different activity patterns, we are focusing especially on ecological constraints and advantages. Also, we stress the necessity of more field observations.

It is shown that reaction of rodent populations to throw is defined by the character and depth of specialization to biotopes of every species. The general consequence of spotting habitats owing to cuttings down for the most of rodent populations is a reorganization of population structure in a metapopulation, which is revealed in the changes of population parameters. Such reorganization of populations has an adaptive character, which allows supporting the optimal structure in a population nucleus.

The amount of phytomass removed by a complex of livestock (horses, cattle, sheep, and goats) and wild ungulates (Mongolian gazelle Procapra gutturosa Pall.) grazing in plain and mountain pastures of eastern Mongolia has been estimated by taking account of feces deposited by these animals. The results show that at an animal density of up to 30 head/km2, the total annual amount of feces reaches 140 kg/ha (dry weight), with the greater part (up to 90 kg/ha) being deposited by horses. The contribution of Mongolian gazelles in some pastures reaches 20–40 kg/ha per year. Decomposition of feces proceeds very slowly, with the annual loss of their weight averaging only 9–12%. This is evidence for gradual accumulation of nondecomposed matter in the soil. The removal of phytomass by the complex of ungulates, calculated from the amount of feces with regard to their annual loss and forage digestibility, varies in different grazing areas from 240 to 400 kg/ha (25–60% of the total aboveground phytomass). The greatest amount of phytomass is utilized by horses, reaching 200 kg/ha (13%), and Mongolian gazelles utilize up to 86 kg/ha per year. In the growing season, ungulates remove no more than 11–16% of the total aboveground phytomass. It is concluded that the impact of total ungulate stock does not impair the productivity of vegetation in the pastures studied.

The mortality of Mesocricetus raddei on two adjacent plots of agrolandscapes (agricultural fields and boundary slopes) in mountainous Daghestan in winter was analyzed. It amounted to 34-51% on slopes, 81-87% in fields and was stipulated by the autumn fatness of the hamsters (r = 0.71-0.81; p < 0.01). The latter was higher in individuals on slopes. During the whole period of activity, hamsters on slopes were provided with a sufficient stock of fodder, in the fields, a food deficit was noted in mid-summer. The food deficiency was responsible for the autumn fatness of animals in fields. As a result, in spite of the low population density on slopes (80-91 ind/ha compared to 100-130 ind/ha in fields slopes), their density was higher there (39-52 ind/ha; 16-25 ind/ha in fields). Stability of the population is mainly a function of its social heterogeneity.

Two adjacent test plots of agrolandscapes in a mountain region of Daghestan (field and boundary slope) were investigated. The intensity of the hamster reproduction (80-90%) and its summer mortality on these plots did not: differ significantly (P > 0.05). Nevertheless, in summer the number of animals on boundary slopes was always higher (39-52 ind/ha) than in field (16-25 ind/ha), but in autumn in fields the number of them was 100-130 ind/ha, on slopes, 80-91 ind/ha. The autumn distribution of animals is shown to be determined by the pattern of intrapopulation relations. On boundary slopes, the developed system of permanent burrows is presented. It is used by hamsters from generation to generation. After hibernation (May-June), boundary slopes are occupied by individuals with the highest social status. During summer, the part of one-year-old animals and of old (3-4-year-old) ones as well as the majority of the young animals are displaced from slopes to fields. Such a mechanism protects slopes against overpopulation and provides the optimal population structure. On each test plot, the spring population density is related to the winter mortality of hamsters.