Long-Term Dynamics of the Midday Gerbil (Meriones Meridianus Pall

INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 9, ISSUE 03, MARCH 2020 ISSN 2277-8616 Long-term Dynamics of the Midday Gerbil (Meriones meridianus Pall) Population in the Portion of the Kyzylkum Desert in the Nukus Area Ruslan Makhsetbaevich Yesimbetov, Gapbar Asenovich Asenov, Baltabay Djanabayevich Allamuratov, Gayrat Jamaladdinovich Matrasulov Abstract—The article provides material on the long-term dynamics of the Midday Gerbil (Meriones meridianus Pall) population in the portion of the Kyzylkum desert in the Nukus area obtained for 54 years, during which period some catastrophic changes have taken place in the regional environment, primarily, those associated with the shrinkage of the Aral Sea. The study includes changes in the animal’s range and numbers. Index Terms— Meriones meridianus, Aral sea, tamarisk gerbil, populations, xylophagous insects, termites. —————————— —————————— 1 INTRODUCTION idday Gerbil inhabits most of the portion of the 9], which is, probably, connected with the species’ association M Kyzylkum desert in the Nukus area. This is a common with sandy landscapes in Middle Asia [10], where their species in the Eastern Caucasus, Kalmykia, Astrakhan numbers fluctuate more strongly than in the semi-desert. Province, the southern part of the watershed between the It rarely occurs in deserts with hard soils and can be found Volga and the Ural and the entire territory of South only on patches of sand [11] or small sandy areas [12, 13, 14, Kazakhstan and Middle Asia. This is a typical inhabitant of 15]. various types of sands, immobile and driving, hilly and ridgy, Of the 10 subspecies inhabiting the territory of CIS, only fixed to a different degree with vegetation. It is particularly one occurs in Karakalpakstan – Meriones meridianus abundant in the sands between the Volga and the Ural where, penicilliger et Heptner. like Tamarisk Gerbil, it is one of the basic components of the Records of Midday Gerbil in the Kyzylkum desert are local biocoenosis. given in the following works [12, 15, 16, 17, 18, 19, 20, 21]. The northern boundary of its range runs in the Jety-Konur sands in the southern portion of the Balkhash lake area, 2 MATERIALS AND METHODS including the Alakol depression. In the territory of CIS (former USSR) it reaches altitudes of 600 m, while in Mongolia it In the field environmental studies of the study, N.V. Novikov occurs at up to 1,600 m above sea level [1, 2, 3]. (1953) used the method of field ecological research. The The size and dynamics of different populations of this permutation of large sand mice per hectare is calculated by species varies across the range. It is distributed evenly in the determining the number of large sand mice living in colonies sands between the Volga and the Ural [4], where Midday that are spaced at a distance of 40 m. The number of small Gerbil is the main carrier of plague [5]. In the Karakum and mice perpendicular, the domestic mice trapped in 100 lashes is Kyzylkum deserts and in the north-west of the Caspian region calculated as a percentage and is calculated at 0.25 and 0.50. Midday Gerbil is a secondary carrier of this disease [5, 6, 7, 8, 3 RESULTS AND DISCUSSION ———————————————— A widespread and abundant species in the Kyzylkum desert Ruslan Makhsetbaevich Yesimbetov, Doctoral candidate, Department of in general and its portion in the Nukus area, in particular, for General Biology and Physiology, Karakalpak State University, Nukus, Uzbekistan. its biological, ecological and phonological features this species E-mail: [email protected] is highly important from both the epizootological and Gapbar Asenovich Asenov, Doctor of Biological Sciences, Professor of the epidemiological aspects. In addition, it plays an important Department of General Biology and Physiology, Karakalpak State University, part in desert biocoenoses, as it feeds on wild fodder plants Nukus, Uzbekistan. and seriously damages pastures. Over 1 kg of locoweed was Baltabay Djanabayevich Allamuratov, Independent Researcher, Assistant of the Department of General Biology and Physiology, Karakalpak State discovered in some of its burrows (Fig. 1). University, Nukus, Uzbekistan. Also, they live xylophagous insects, especially found in Gayrat Jamaladdinovich Matrasulov, Doctoral candidate, Department of termite nests [22, 23]. General Biology and Physiology, Karakalpak State University, Nukus, Changes in the long-term and seasonal dynamics of the Uzbekistan. Midday Gerbil population depend on the abundance of wild plant seeds. As these seeds are Midday Gerbil’s basic food, cellular and ridgy sands with large dunes and broad and deep cells and ridgy and cellular sands with small dunes and broad depressions between ridges are favourable for the species’ 6213 IJSTR©2020 www.ijstr.org INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 9, ISSUE 03, MARCH 2020 ISSN 2277-8616 subsistence, and the animal’s numbers grow strongly when The outskirts of the sandy area on the border between the the abundance of herbs and shrubs is high (Fig. 2). desert and oasis consisting of a mosaic of biotopes with richer vegetation differ in this respect from other territories. In these habitats Midday Gerbil is abundant and its numbers are stable (Fig. 3). The analysis of autumnal observations during the 54-year period showed that the high (above 10%) average rate of capturing Midday Gerbil during 100 camera trap-nights was recorded 10 times in 54 years, medium rate (5-10%) – 13 times, and low rate (1-5%) 31 times (Table 1, Fig. 4). In certain years (1964, 1965, 1969, 1979, 1980, 2003, 2011, 2013), when the rate of precipitation was equal to or above average and seed-bearing herbaceous plants were more abundant, the capturing rate during 100 camera-nights reached 20% and even 35-50% (Table 1, Fig. 4). In these years high numbers of Midday Gerbil were Fig. 1. The bag contains the seeds of locoweed (Astragalus recorded not only in the Nukus area, but also on the Beltau unifaliolatus Bunge 1847) found in the burrow of a midday gerbil. elevation in the western part of the Kyzylkum desert and on the outskirts of some other portions of Kyzylkum. The material obtained during the long period demonstrates high abundance of Midday Gerbil throughout the Karaklpakstan portion of the Kyzylkum desert. The abundance of Midday Gerbil is quite high in the Nukus area, on the Beltau elevation and in the western part of the Kyzylkum desert, but it is considerably lower in geographic areas and ecological regions farther northwards (Table 2). As a typical psammophil, Midday Gerbil is more abundant in the mentioned areas than in other transitional biotopes on the border between the desert and oasis (Fig. 3). Fig. 2. A map of the portion of the Kyzylkum desert in the Nukus area and the distribution of Great Gerbil colonies in various parts Fig. 4. Long-term changes in the Midday and Great Gerbils The biotope of ridgy and cellular sands features broad populations in the portion of the Kyzylkum desert in the Nukus area. depressions between the ridges, where contacts within and between animal species are closer because of the absence of deep cells and high dunes preventing these contacts. The Figure 3 above demonstrates the seasonal dynamics of sands are fixed with shrubs and semi-shrubs and annual and Midday Gerbil population in three biotopes. In sandy desert perennial herbs. The area is inhabited by 24 mammal species. biotopes and in biotopes on the border with the oasis it is The average density of the colonies is 1.5-2.0; 10-15 more abundant throughout the year than in oasis [9]. individuals of Great Gerbil were recorded on 1 ha; Midday The cyclic development of the long-term dynamics of Gerbil – 15-20% per 100 camera trap-nights [8, 9]. Midday Gerbil population, which consists of a longer period and a shorter period, deserves special mentioning and study. The situation in the long cycle repeats itself every 13-15 years and lasts 1-2 years, and that in the short cycle repeats itself every 2-4 years and lasts 2-3 years (Fig. 3). During the long cycle Midday Gerbil’s abundance is very high and amounts to 15, 20, 30%, while during the short cycle the capturing rate is 5-10% during 100 camera-nights. During low years the abundance of Midday Gerbil Fig. 3. Seasonal variations in the numbers of Midday Gerbil in decreased sharply in both cycles and the capturing rate was different biotopes. not more than 0.1-1.1%. 6214 IJSTR©2020 www.ijstr.org INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 9, ISSUE 03, MARCH 2020 ISSN 2277-8616 TABLE 1 In the portion of the Kyzylkum desert in the Nukus area LONG-TERM AND SEASONAL DYNAMICS OF THE MIDDAY GERBIL POPULATIONS IN THE PORTION OF THE KYZYLKUM DESERT IN THE higher abundance in the long cycle was recorded in 1964-1965 NUKUS AREA and 1979, and after that for 20 years the abundance remained low. All this was caused by the shrinkage of the Aral Sea and the resulting climate changes, degradation of ecosystems, aridisation and desertification, and worsening of environmental conditions. Extremely dry air, hot winds and saline soils had a serious impact on the quantity and quality of plants eaten by all types of animals, and that became a crucial factor in the life of all animal species in the southern portion of the Aral Sea area. There is asynchronicity in the dynamics of the numbers of Midday Gerbil and Greater Gerbil in the portion of the Kyzylkum desert in the Nukus area. Great Gerbil is an abundant diurnal species able to form the environment. The only species that can be compared to it in abundance is the nocturnal Midday Gerbil.

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