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Spatial distribution of mole rat (Spalax microphthalmus) mounds and soil penetration resistance. – Zhukov A. V., Kunah O.N., and Konovalova T. P. – Point pattern geostatistics was used to describe the spatial distribution of mole rat (Spalax microphthalmus) mounds. The Poisson and Widom – Rowlinson processes are discussed as alternative models. The spatial pattern of mole rat mounds is an aggregated structure with a regular distribution within every aggregation. The soil penetration resistance at a 25 – 50 cm depth affects the intensity of the mole rat pedoturbation activity: as the resistance decreases, the activity increases. In turn, the soil hardness within the 0 – 10 cm layer decreases with increasing mole rats’ pedoturbation activity.
Key words: pedoturbation activity, spatial point process, Ripley function, soil penetration resistance.
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Similarity of the bird breeding range boundaries and the summer month isotherms in the tundra zone of the Western-Siberian plain. – Zhukov V. S. – For 111 bird species (80% of the total number of breeding species), their southern and northern boundaries of breeding ranges resemble the summer month isotherms in 23 and 91 cases, respectively. Of these 23 similarity cases of the southern boundaries, 8, 11, and 4 cases show similarity to the isotherms of June, July, and August, respectively. Of the 91 similarity cases of the northern boundaries, 28, 55, and 8 cases show similarity to the isotherms of June, July, and August, respectively. In both bird groups (in the case of similarity of the summer month isotherms with the southern and northern range boundaries) the average weight of the birds whose range boundaries are close to the isotherms of June (the coldest summer month), 1,384 and 985 g, respectively, is by 3 – 3.2 times higher than that of the birds whose range boundaries are close to the isotherms of July (the warmest summer month), 430 and 329 g, respectively. The average weight of the birds whose breeding range boundaries are close to the isotherms of August, the temperature-average summer month, in both cases increases again, by 1.2 and 1.7 times, respectively (up to 535 and 546 g). For the largest bird species (Anseriformes), the northern range boundaries are only close to the June and July isotherms (10 and 8 cases, respectively). For smaller birds (Charadriiformes), their northern range boundaries are also close to the June and July isotherms only, but July somewhat predominates (7 and 11 cases, respectively). For the smallest birds (Passeriformes), the majority of coincidences of their northern boundaries to the summer month isotherms are revealed for July (28); in June and, especially, in August this number is much lower (7 and 3, respectively). For Falconiformes, the number of similarity cases of its northern range boundaries to the isotherms is more uniform from June to August (3, 4, and 2 cases, respectively).
Key words: birds, breeding ranges, isotherms, tundra zone.
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Influence of bird trophic connections on their helminthofauna in the delta of the Volga and the North Caspian Sea. – Ivanov V. M., Kalmykov A. P., and Semyonova N. N. – The influence of nutrition on the bird helminthofauna in the delta of the Volga River and the North Caspian Sea was studied. The high degree of invasion and the specific variety of helminthes were found to be characteristic of the birds with the highest variety of their feed. According to nutrition character, we can judge on the helminthofauna, and helminthofauna analysis provides an insight into nutrition ingredients.
Key words: birds, trophic connections, helminthes, invasion degree.
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Perennial abundance dynamics and the modern state of small mammalian species in lowland swamps of the Usmansky pine forest (Voronezh region). – Klimov A. S. – The results of our accounting of small mammalians in five lowland swamps of the Voronezh University biocentre surroundings in 1988 – 2011 are presented. 16 species of rodents and insect-eating mammals were registered in the total. Clethrionomys glareolus, Sorex araneus, Sylvaemus uralensis, and Sylvaemus flavicollis are most typical. Apodemus agrarius and Sorex minutus were scarce. C. glareolus was most abundant and widespread in the pine forest. The second place was occupied by S. flavicollis, the third one by S. araneus, with S. uralensis and A. agrarius to follow. The abundance of all species was subject to sharp oscillations, and a trend of its decrease was observed.
Key words: small mammals, abundance, Voronezh region.
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Little Bustard population restoration in the northern steppe Trans-Urals. – Korovin V. A. – The dynamics of a little bustard population in the northern steppe Trans-Urals is considered. After some period of its almost complete absence in the 1970s and 1980s, since the early 1990s, temporarily empty parts of the habitat have been inhabited again and an increase in the population is observed. By the beginning of the 21st century, the Little Bustard almost restored its previous habitat in the region. By the end of the 1990s, the average population density over the agro-landscape reached 1 ind/km2. By the end of the first decade of the 2000s it exceeded 2 ind/km2. In recent years, the Little Bustard is rarely observed in steppe pastures but can more often be met on long-term grass crops and reaped grain fields, and the most part of its population (up to 70 – 80% of all couples) inhabits fallow lands whose appearance and preservation are due to the steady reduction of the agricultural industry over the last two decades.
Key words: Tetrax tetrax, number, population density, biotopic distribution, steppe Trans-Urals.
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Effect of atmospheric precipitations and the abundance of a semi-aquatic bird colony on zooplankton in the littoral of a small high-trophic lake. – Krylov A. V., Kulakov D. V., Tsvetkov A. I., and Papchenkov V. G. – It was found that when the atmospheric precipitation amount increased the changes in zooplankton indices in the background area in the littoral zone of a small high-trophic lake were similar to those observed under an increased organic and biogenic load in the course of anthropogenic eutrophication: the diversity and abundance of rotifers increased and the indices of copepods’ development decreased. In the area subjected to the effect of bird vital activity products an increase in the colony abundance and surface flow reduced the number of species (due to the diversity of rotifers and copepods), the numbers and biomass of zooplankton, the fraction of Rotifera and Cladocera in the total numbers and biomass of the community, and Shennon’s index – but increased Copepoda development indices. Atmospheric precipitation reduction at both sites of the littoral zone led to a decreased Copepoda abundance and increases numbers of Rotefera and/or Cladocera. However, in the heron breeding colony area the zooplankton was characterized by the highest development of copepods and the lowest one of rotatoria and cladocera.
Key words: zooplankton, taxonomic groups, atmospheric precipitation, semi-aquatic birds, vital activity products.
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Dreissena veligers in the upper Volga reservoirs: long-term and seasonal abundance dynamics and distribution. – Stolbunova V. N. – Long-term and seasonal data on the abundance dynamics of Dreissena larvae in the Ivankovo, Uglich and Rybinsk reservoirs are presented. Veligers emerge in June at water temperatures not lower than 15°C or, in some years with a warm and early spring, they appear in May. Two peaks of the larvae abundance are observed in the pelagial and littoral parts of the reservoirs: at the beginning of July and (the highest peak) at the beginning of September. In the bay mouths the highest abundance peak occurs at the end of July, and the next peak is at the beginning of September. The larvae are distributed nonuniformly and prefer surface layers with a maximum at the night time. Since the 1990s, the numbers of Dreissena larvae have increased notably in the Ivankovo and Uglich reservoirs.
Key words: reservoirs, Dreissena larvae, distribution, seasonal abundance dynamics.
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Food abundance influence on the distribution of flying waders on water treatment facilities in a forest-steppe zone. – Sucharev E. A., Spiridonov S. N., and Okolelov A. Yu. – The dependence of the distribution of flying waders on water treatment facilities in European Russia on the character of their food reserve was studied. Data about the distribution dynamics of waders and their food resources, the nutrition behavior of these birds, the contents of their stomachs and gullets are provided.
Key words: waders, food, industrial wetlands, forest-steppe zones.
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ABC method and the domination specificity of species in bottom river communities. – Shitikov V. K. and Golovatyuk L. V. – The results of using cumulative curves of the Abundance/Biomass Comparison (ABC) method to test the ecological status of potamiums, to evaluate the probability of stressful impacts, and to quantitative estimate the ratio of species with opposite vital strategies are given. The abundance and biomass curves are shown to be close to each other for the communities dwelling on rather clean river sites, and the W-statistics does not differ from zero reliably. The domination of species with a high individual weight, in particular, bivalved mollusks, is a sign of structurally functional changes in the benthos communities of polluted reservoirs, which essentially contradicts the theoretical bases of ABC. The causes of this incorrectness of our ecological status estimation of river biocenoses by Warwick’s method are analyzed, this method not considering the specificity of domination mechanisms in the macrozoobenthos communities of river systems. Examples of rejecting the hypothesis of k-strategists determining the basic character of biocenotic processes in pure ecosystems are given, whereas in polluted ones the species with the r-strategy of their life cycles start to prevail.
Key words: river zoobenthos, abundance, biomass, dominance curves, ABC method, community structure.
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