The Food Resource Status and Nutrition Selectivity in the Midday Gerbil (Meriones meridianus) in Arid Conditions of the Northwestern Caspian Region

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.