The State of Food Resources and Reproductive Success of Tufted and Horned Puffins in the Northern Sea of Okhotsk

Studies on the reproductive biology of seabirds on Talan and Umara islands in 1987–1999 showed that the diet of nestlings and reproductive success of the tufted puffin (Lunda cirrhata) and horned puffin (Fratercula corniculata) considerably varied in different colonies. This was determined by differences in the hydrologic characteristics of water areas and the state of food resources in Taui Bay (the northern Sea of Okhotsk). The reproductive success of tufted puffins was higher on Umara Island due to more favorable environmental conditions and relatively stable food resources in Odyan Bay. The parameters of reproductive success and the nestling diet in tufted and horned puffins from Talan Island differed considerably. The survival of nestlings was always higher in horned puffins, which was related to some characteristics of their feeding ecology.     

Growth of the nesting colony of slaty-backed gulls (Larus schistisagus) and plant cover degradation on Shelikan Island (Taui inlet, the Sea of Okhotsk)

The size of Larus schistisagus nesting colony on Shelikan Island (8 ha in area) has increased from 2000 to 6000 pairs over 18 years. Today, this is the largest colony in the Sea of Okhotsk. The growth of the bird population has entailed catastrophic deterioration of the plant cover accompanied by a decrease in the species diversity of vascular plants: more than one-third of plant species recorded on the island in 1986 have already disappeared, and the establishment of several new plant species cannot compensate for this loss. If the size of the colony increases further, woody vegetation will fully deteriorate and only a thinned herbaceous layer consisting of 15–20 most resistant species will remain on the island.     

Problems of Population Dynamics of the White-Eyed Pochard (Aythya nyrocaGuld., 1770) in the Eastern Sea of Azov Region

The long-term population dynamics of the white-eyed pochard (Aythya nyroca) in the eastern Sea of Azov region was analyzed. It was found that the local population of this species tends to decrease in size. Clutch size, egg size, reproductive behavior, intraspecific clutches, embryonic mortality, and hatching success in this population were studied. The contents of PCDD and PCDF in the eggs of waterfowl were estimated. The eggs of white-eyed pochard, compared to other waterfowl, proved to contain abnormally high concentrations of xenobiotics. Possible causes of A. nyrocapopulation decline, including the impact of superecotoxicants, are discussed.     

Distribution of White Whales (Delphinapterus leucas) in the White Sea and the Southeastern Region of the Barents Sea during the Ice Season

The habitats, relative occurrence, and distribution of the white whale in the White Sea and the southeastern Barents sea in every month of the ice season have been studied using the results of an aerial ice survey along standard routes from 1970–1991. In these seas, white whales have been found in each month of the ice season, with single animals, groups, schools or gams, herds, and large congregations of several hundred animals accounting for 10, 22.8, 47.2, 12.9, and 7% of all aggregations of white whales observed, respectively. The relative occurrence of white whales in the White Sea is higher in March and May (32.5 and 30%, respectively) and lower in February, January, and November (15, 10, and 7.5%, respectively); in December and April, the whales are observed very seldom (2.5% in both months). In the southeastern Barents Sea, the relative occurrence of white whales is highest in May (53.3%) and considerably lower in December and February (16.7 and 10%); only a few animals are found during the remaining ice season. Regarding different habitats, the relative occurrences of white whales in open water, in water openings in the ice, near the edge of pack ice, and in ice packs with different degrees of closeness are 21.5, 11.4, 45.7, and 21.4%, respectively.     

Ecological and genetic characteristics of the distribution of <Emphasis Type="Italic">Bradybaena fruticum</Emphasis> Mull. (mollusca,gastropoda, pulmonata) in a forest-steppe landscape

The distribution pattern of the gastropod Bradybaena fruticum has been studied in a forest-steppe landscape. Analysis of the frequencies of polymorphic biochemical and conchological characters has yielded preliminary results on the characteristics of the species population structure whose formation was determined by a set of natural and anthropogenic factors.Translated from Ekologiya, No. 1, 2005, pp. 39–47.Original Russian Text Copyright © 2005 by Snegin.     

Structure of the communities of small mammals (micromammalia) in forests on western slopes of the Northern Urals

Long-term data on the species composition and ratio of insectivores and rodents in forest ecosystems of the western macroslope of the Northern Urals are considered. It is shown that the micromammalian communities of mountain forests are characterized by higher total abundance and polydominance and comprise greater numbers of common species than the communities of taiga forests in neighboring regions of the Russian Plain. Hence, the mountain-forest communities of small mammals have high indices of species diversity and uniformity.Translated from Ekologiya, No. 2, 2005, pp. 138–145.Original Russian Text Copyright © 2005 by Bobretsov, Lukyanova, Poroshin.     

Variation in the Parameters of the Life Cycle in Prawns of the Genus MacrobrachiumBate (Crustacea, Palaemonidae)

Variations in the parameters of the life cycle in freshwater prawns of the genus MacrobrachiumBate and some populations of the species Macrobrachium nipponense(De Haan) were analyzed comparatively. Using factor analysis, these parameters were systematized and expressed through two factors. The first factor is related to the parameters of larval development and the dimensions of an egg, and the second, to the length of adults and their fecundity. The greatest differences in the values of intrageneric and intraspecific variation of parameters are noted for the dimensions of larval stages. It is assumed that the formation of a species proceeds primarily through the appearance of adaptations at larval stages.     

Effects of the Anthropogenic Factor on Bats (Chiroptera: Vespertilionidae) in the Volga Region

Using the example of bats inhabiting the Volga region, the cases in which the anthropogenic factor creates favorable conditions for these animals or significantly reduces their diversity of their fauna are considered. In this context, an opinion concerning the approaches to the conservation of bats is formulated.     

Medieval Agroecosystems (9th–13th Centuries) in the Region of the Present-Day City of Glazov (Udmurt Republic)

Paleoethnobotanical materials and buried soils from the site of the ancient settlement of Idnakar and neighboring archaeological monuments were analyzed to reconstruct the agroecosystems of the 9th through the 13th centuries AD near the present-day city of Glazov. The results provided data on the main features of the agroecosystem structure and composition, climate, and agriculture in the Middle Ages.     

Fluctuations of Population Size and Structure in the Northern Mole Vole: Preliminary Analysis

Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants.     

Caddis flies (Trichoptera) in the benthos and food of fish from streams of the Pechora-Ilych State Biosphere Reserve, the northern Urals

Data on the numbers and biomass of caddis fly species (Trichoptera) in the benthos and in the diets of fish from streams of the Pechora-Ilych State Reserve (the northern Urals) are provided. In the diets of grayling and juvenile Atlantic salmon caught in the rivers of the reserve, 17 and 10 species of caddis flies have been identified. As a rule, one to three species (in most cases, two species) prevail in the diet of fish.     

The spatiotemporal structure of population in the Muskrat (Ondatra zibethicus)

The spatiotemporal structure of the muskrat population has been studied by means of the prenatal radioactive marking of juveniles with 45 Ca and their subsequent recapture in the test area. The muskrat population is characterized by a cyclic type of spatial structure, with seasonal transition from a mosaic type of settling to a diffuse type and, after the breeding season, vice versa.     

Energy metabolism and growth of Monoporeia affinis Lindstr. in the Northern Lake Krivoe (Karelia)

The physiological method for estimating production based on the relationship between growth and energy metabolism has been used for calculating model growth curves for the amphipod Monoporeia affinis and comparing them with the results of field studies. Calculations demonstrated that the physiological growth curves fit the results of field observations best under certain conditions which have zoological sense: the growth curve should reflect the actual maximum body size of an animal in the given population, the duration of the life cycle, and the time required for reaching the reproductive size.     

Variation of short-lived beta radionuclide (radon progeny) concentrations and the mixing processes in the atmospheric boundary layer

Radon is emitted to the atmosphere with quasi constant emission rates depending on the radium concentration in the earth's crust and soil physical properties. In this way, the ²²²Rn and ²²⁰Rn concentration in air reflects significantly the thickness of the atmospheric boundary layer (ABL). The aerosol-associated, beta-emitting progeny nuclides of ²²²Rn were measured daily in the framework of the atmospheric radioactivity monitoring program of NIMH at Sofia. The ²¹⁴Pb concentration was estimated from the measured short-lived beta activity of 24-h filter samples, changed daily at 6:00 GMT. The impact of some meteorological factors such as wind direction, wind velocity, humidity, and temperature on short-lived beta radionuclides is estimated, and the results show no simple statistical relationship. A seasonal pattern was observed with winter minima and late summer-early autumn maxima. High variability in daily morning concentrations and mean monthly values was observed. There were well pronounced differences between years. The height of the convective ABL was estimated from daily radio-soundings at 12:00 GMT for the period 2001-2006 and from seven soundings per day during the experimental campaign in Sofia in October 2003. In general, concentrations of short-lived ²²²Rn progeny nuclides decreased with increased convective ABL height.     

Intrapopulation Differentiation by the Rates of Rosette Growth and Individual Plant Development in Narrow-Leaved Hawk’s Beard (<Emphasis Type="Italic">Crepis tectorum</Emphasis> L.): Aftereffects of Long-Term Stress

Aftereffects of exposure to long-term chemical pollution with fluorine and sulfur compounds on intrapopulation differentiation of the rates of growth and development has been studied on Crepis tectorum L. progenies obtained from seeds collected in a pollution gradient and grown in a greenhouse under uniform ecological conditions. The results have shown that long-term stress (exposure to toxic gaseous pollutants) leads to significant changes in the intrapopulation structure, which are manifested in an increase in the proportion of plants with a low rate of development, a low relative rate of the linear growth of metameres (leaves), but a higher relative rate of their formation.__________Translated from Ekologiya, No. 4, 2005, pp. 243–251.Original Russian Text Copyright © 2005 by Trubina.