No 1 (2025)
Articles
SEASONAL AND INTERANNUAL DYNAMICS OF THE FEEDING SPECTRUM OF A PAIR OF GROUND EAGLES (AQUILA HELIACA, ACCIPITRIDAE, ACCIPITRIFORMES) IN THE RIGHT BANK OF THE MIDDLE VOLGA REGION (SENGILEEVSKY MOUNTAINS)
Abstract
The food supply is a key factor determining the reproductive performance of populations of the large feathered predators. The distribution of the Imperial Eagle Aquila heliaca is primarily limited by the distribution and abundance of the main prey species, namely large colonial steppe rodents (ground squirrels and marmots). Despite the wide adaptive capabilities of the Imperial Eagle for food supplies, the role of secondary prey species in feeding of the young remains an urgent research topic. Modern methods of autonomous video surveillance used in this work enabled exploring the diet of a pair of the Imperial Eagles in the Sengileevsky Mountains National Park. The studies were conducted in 2023-2024 in the period from March to September. An autonomous video surveillance system was used for the observations. During the entire observation period, 444 prey items brought by the adults to the nest were recorded, of which 428 items were identified to the species, genus, family, order or class. 34 items of wild fauna belonging to 4 classes of vertebrates were identified in the diet of a pair of the Imperial Eagles. The maximum food intake is observed in June and July. The main prey items are Russet ground squirrels (20 %), common field voles (19 %) and steppe marmots (12 %). Large steppe rodents predominate in the diet at the initial stages of feeding of hatchings (June). The proportion of large birds in the diet increases significantly during the feeding period of nestlings and fledglings (July-August). When raising two offerings, compared with one, there is a multiple (by an order of magnitude) increase in the number of large birds in the diet of the Imperial Eagles in the late stages of feeding nestlings and fledglings. Despite the adaptability of the Imperial Eagles in choosing prey items, large rodents of open spaces remain one of the key food supplies. Large steppe rodents, mainly colonial ones, ensure the continuity of feeding the young during the most critical period of their development. The diet of the Imperial Eagles can include almost the entire range of vertebrates found in the breeding territory of a pair.
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CHANGES IN THE NUMBER OF WILD UNGULATES IN THE SOUTHWEST PRIMORSKIY PROVINCE, RUSSIA
Abstract
Management of populations of rare predators is impossible without knowledge of the number and density of their main prey species. In the Southwest Primorskiy Province, the world's only wild population of the Far Eastern leopard has been preserved, and the area is also part of the range of the Amur tiger. The main hunting objects of these rare predators are ungulates: sika deer, roe deer, wild boar. In 2019, a new ungulate species for Primorskiy Krai and Russia – the water deer – was discovered here. The aim of the work is to study the number and density of wild ungulates in the range of the Far Eastern leopard, to assess the dynamics of changes that have occurred in the populations over 3 years. Materials from two full-scale aerial surveys conducted in 2019 and 2023 were used to estimate the number and density of wild ungulates in the Southwest of Primorskiy Province. The survey routes covered the entire Russian part of the range of the Far Eastern leopard with an area of 571,000 ha, including hunting grounds and protected areas of national and provincial levels. Both surveys were conducted using the same methodology and under as identical conditions as possible. In 2019, the total length of the routes was 1104.8 km and 1298 sika deer, 264 roe deer, 301 wild boar and 11 water deer were encountered. In 2023, 1666 sika deer, 151 roe deer, 71 wild boar and 19 water deer were registered along 999.6 km. Since 2019, sika deer numbers have increased by 25 % to 28.9 thousand individuals at a density of 50.5 ind/1000 ha. Favorable conditions for population growth are created by highly productive oak-broadleaf forests, lack of stable snow cover in winter, as well as additional winter foraging and improvement of anti-poaching work on protected areas. At the same time, the roe deer number and density declined twofold, and by 2023 here was 2.8 thousand individuals at a density of 4.8 ind/1000 ha. The main reasons for the population decline are competitive relationships with sika deer, as well as hunting and poaching pressure outside the specially protected natural areas. As a result of the outbreak of African swine fever, the number of wild boar in the Southwest Primorskiy Province has decreased more than 4 times in three years to 1.3 thousand individuals at a density of 2.3 ind/1000 ha. Water deer population in the south part of the study area was doubled in three years and totaled about 300 individuals at a density of 2.8 ind/1000 ha. Despite the depression of wild boar and roe deer populations, due to the growth of sika deer numbers, the total population of wild ungulates in 2023 remained at the level of 33 thousand animals, which provides prey for the growing populations of the Far Eastern leopard and Amur tiger. The number of sika deer in the study area reached a historical maximum. The population growth indicates that the south-west of Primorskiy Province has the most favorable conditions for this species. With the increasing population of sika deer, roe deer will continue to be displaced from forested areas into open habitats. It is likely that the core roe deer population will remain in rare forests and meadow habitats in the south of Khasanskiy District. It is not known whether the ban on wild boar hunting announced in Primorskiy Province will affect the recovery of the population of this species. The prognosis for the outcome of the disease and the recovery of animal numbers is currently unclear. The rapid growth of the water deer population in the Russian part of its range is not surprising. The combination of favourable environmental factors is complemented by early puberty and high fertility of animals.
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CHANGE OF MICROBIAL FORMATIONS IN ORGANIC POULTRY WASTE MATERIALS DURING NATURAL DEGRADATION PROCESSES
Abstract
The intensive production of food protein is an integral attribute of modern civilization. Poultry meat production is developing most dynamically all over the world and in Russia, in particular, because this industry is characterized by a short reproduction cycle and quick payback of invested funds. However, the growing rates and volumes of production also entail a progressive increase in waste masses. Litter and poultry litter are transported to landfills or directly to the fields, where over time they undergo natural degradation, accompanied by the emission of gases into the atmosphere and biogens into the soil and groundwater. The ingress of biogens and indigenous microflora of manure into the soil leads to changes in the composition of biocenosis components and the characteristics of their biotopes. The rate and efficiency of degradation depend on the enzymatic potential of the microflora present and the integral effect of endogenous and exogenous factors. Purpose of research: study of dynamics of species composition and environment-forming role of microflora of organic wastes of poultry farming in the processes of their natural destruction and consideration of factors determining the change of formations. In the process of work the following tasks were solved: study of indigenous microflora of poultry litter, study of composition of autochthonous, allochthonous and zymogenic microflora, study of microflora role in formation of substrate transformation vector (reaction and medium temperature), evaluation of microbial formation change regularities. The role of indigenous microflora of manure in the processes of ammonification as a starting stage of degradation of nitrogen-containing waste mass was established. From the process of ammonification starts the step-by-step degradation of manure-litter mixture. The shift of the pH range to the alkaline region caused by the activity of ammonifiers is a factor preventing the proliferation of fungal microflora and degradation of hard-to-degrade polymers. Exposure to high temperatures in the thermal phase of substrate composting is a selection factor sharply modifying the species composition and determining its deep reorganization. The determining role of autochthonous soil microflora at the final stages of organic waste degradation has been established. Species diversity of microorganisms in the masses of organic wastes naturally changes at different stages of degradation. The rates of microbial formations change decrease as the material decomposes, and the dynamic equilibrium of microflora composition is associated with the achievement of a stable balance of biogenic elements, mainly nitrogen and carbon.
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VARIANTS OF GENERATIVE SHOOTS OF BOREAL WILLOW SPECIES (SALICACEAE)
Abstract
The structural and functional organization and dynamics of the development of generative shoots in boreal willow species have not been sufficiently studied yet, which determined the aim of the study. The structure of spring generative shoots of regular renewal and summer secondary flowering generative shoots was examined in 16 species of boreal willows. Attention was paid to the time of the appearance of generative shoots, the length, the degree of vegetation and the duration of the vegetative zone. In S. myrsinifolia, the location of male and female flowers in bisexual inflorescences and the location of generative shoots (male, female, and bisexual) in the plan shoot system were revealed. The study found that the examined willow species can develop, in addition to generative shoots of regular renewal, secondary flowering generative shoots. Generative shoots of regular renewal are divided into single-stage falling (S. caprea, S. vinogradovii, S. gmelinii, S. acutifolia, S. viminalis, S. aurita, S. lapponum), two-stage falling (S. alba, S. euxina, S. triandra, S. cinerea, S. myrsinifolia, S. starkeana, S. rosmarinifolia, S. myrtilloides) and conditionally non-matching (S. pentandra). Among the secondary flowering generative shoots, 5 variants were identified, differing in the length and variety of the vegetative zone. Secondary flowering generative shoots can be divided into summer and late summer shoots according to the time of appearance. In the same species, generative shoots of regular renewal and secondary flowering generative shoots may differ in the structure of the vegetative zone. In S. myrsinifolia, male, female, and bisexual inflorescences can form on the same plant, while generative shoots with male inflorescences develop from both wintering buds and dormant buds. Polymorphism of generative willow shoots is determined by the degree of vegetation and duration of the vegetative zone, the time of formation of generative shoots, the formation of not only unisexual, but also bisexual inflorescences.
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PATTERN OF SPATIAL DISTRIBUTION OF HIBERNATING BATS (CHIROPTERA: VESPERTILIONIDAE) DEPENDING ON AIR TEMPERATURE AND HUMIDITY IN ARTIFICIAL CAVES OF SAMARA LUKA
Abstract
This paper explores the features of bat distribution during hibernating in artificial caves of the Samara Bend (in the Samara Region). Data on microclimatic preferences of 7 species of hibernating bats and their tolerance limits in relation to air temperature and humidity in shelters were obtained, mathematical models of the dependence of bat distribution on the above factors were compiled. The study found that the species Plecotus auritus(Linnaeus, 1758), Eptesicus (Cnephaeus) nilssonii (Keyserling & Blasius, 1839), Myotis daubentonii (Kuhl, 1817) and M. mystacinus (Kuhl, 1817) have a relatively wide tolerance to the temperature of the shelter, relative stenothermy was found for M. dasycneme (Boie, 1825) and slightly less for M. nattereri (Kuhl, 1817). The temperature optimum for most bat species is +2…+4 °C. Species that tend to form clusters or occupy internal microshelters are able to endure hibernation in cooler parts of the caves. All the studied bat species are characterized by high tolerance to air humidity values in shelters.
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