Mating systems in the steppe lemming (<Emphasis Type="Italic">Lagurus lagurus)</Emphasis> and narrow-skulled vole (<Emphasis Type="Italic">Microtus gregalis</Emphasis>) from the Northern Kulunda Steppe

A comparative analysis of reproductive behavior has been performed in the steppe lemming (Lagurus lagurus) and narrow-skulled vole (Microtus gregalis). The results show that the species are similar in certain behavioral features indicative of the stability of mating pairs. However, in the narrow-skulled vole, unlike in the steppe lemming, mature males in olfactory tests show preference for receptive sibling females versus non-kin females. Probably, it is the absence of the incest taboo that allows the involvement of young of the year in reproduction within growing family groups and accounts for “coloniality” of the species.     

Efficiency of natural reproduction of sturgeons in the lower Volga under current conditions

The results are presented that have been obtained during long-term studies (1991–2009) on the efficiency of natural reproduction of the beluga, Russian sturgeon, stellate sturgeon, and sterlet in different spawning zones of the Volga. The influence of major environmental factors on the formation of the offspring of these fishes is analyzed. It is shown that the productivity of Volga spawning grounds varies depending on the river flow volume during spring floods and the abundance of active spawners. Practical recommendations are proposed for enhancing sturgeon reproduction in the Volga.     

Comparative analysis of small mammal communities in Chisinau and Yaroslavl, two European cities located in different biomes

Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses.     

Effect of anthropogenic pollution on oxidative processes in the liver of fish from the Rybinsk Reservoir

The levels of total lipids, peroxidation products, and antioxidant activity in the liver were studied in fish species living in unequally polluted areas of the Rybinsk Reservoir and differing in their ecology and taxonomic position: the bream (Abramis brama L.), roach (Rutilus rutilus L.), burbot (Lota lota L.), and zander (Stizostedion lucioperca L.). The fish from polluted water areas were characterized by higher levels of total lipids and malonic dialdehyde and a deficiency of antioxidants. It is shown that the test parameters depend on the type of feeding and mode of life of the fish species.     

Antlers of Cervus elaphus as biomonitors of ⁹⁰Sr in the environment

Adequate radioprotection of the environment requires the identification of biomonitors sensitive to the variation of its radionuclide content. Due to the chemical similarities between calcium and strontium, calcified tissues of mammals are considered to be good ⁹⁰Sr biomonitors. This work considered Cervus elaphus antlers which, being shed annually, can give information about the importance of radiostrontium contamination in an ecosystem in the time period required for the growth of the antler. The samples were collected at various points of W and SW Spain. The mean value of their ⁹⁰Sr content was (70 ± 43 (S.D.)) Bq/kg d.w., range (16-218) Bq/kg d.w., and the radionuclide was evenly distributed in the different parts of the antler. There was a good correlation between the antlers’ ⁹⁰Sr content and the ⁹⁰Sr deposited in the soil. The antlers’ content of ²²⁶Ra (from the natural uranium series) and the contents of some stable elements (Ca, Mg, Sr, and K) were also determined. The values for these stable elements were practically constant in the analyzed samples, and the concentrations measured decreased in the following order:Ca » Mg > K > Sr » ⁹⁰Sr > ²²⁶Ra     

Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities

In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 × 10⁻⁵ mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures.     

Co-digestion of sewage sludge with glycerol to boost biogas production

The feasibility of adding crude glycerol from the biodiesel industry to the anaerobic digesters treating sewage sludge in wastewater treatment plants was studied in both batch and continuous experiments at 35 °C. Glycerol addition can boost biogas yields, if it does not exceed a limiting 1% (v/v) concentration in the feed. Any further increase of glycerol causes a high imbalance in the anaerobic digestion process. The reactor treating the sewage sludge produced 1106 ± 36 ml CH₄/d before the addition of glycerol and 2353 ± 94 ml CH₄/d after the addition of glycerol (1% v/v in the feed). The extra glycerol-COD added to the feed did not have a negative effect on reactor performance, but seemed to increase the active biomass (volatile solids) concentration in the system. Batch kinetic experiments showed that the maximum specific utilization rate (μ_max) and the saturation constant (K_S) of glycerol were 0.149 ± 0.015 h^?1 and 0.276 ± 0.095 g/l, respectively. Comparing the estimated values with the kinetics constants for propionate reported in the literature, it can be concluded that glycerol uptake is not the rate-limiting step during the process.     

Temperature adaptation of the heart in the grass snake (Natrix natrix L.), common European viper (Vipera berus L.), and steppe viper (Vipera renardi Christoph) (Reptilia: Squamata: Serpentes)

Changes in the heart rate (HR) in more and less thermophilic reptiles (Natrix natrix L., Vipera berus L., and V. renardi Christoph) exposed to heating from 0 to 40°C under anesthesia have been found to depend on the previous adaptation of the animals to the temperature parameters characteristic of the natural habitats of their populations.     

The problem of estimating recent genetic connectivity in a changing world

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g., cost effective) relative to ecological methods. Given the reductions in wildlife population connectivity since the Industrial Revolution and more recent drastic reductions from habitat loss, it is important to know the accuracy of and biases in genetic connectivity estimators when connectivity has declined recently. Using simulated data, we investigated the accuracy and bias of 2 common estimators of migration (movement of individuals among populations) rate. We focused on the timing of the connectivity change and the magnitude of that change on the estimates of migration by using a coalescent‐based method (Migrate‐n) and a disequilibrium‐based method (BayesAss). Contrary to expectations, when historically high connectivity had declined recently: (i) both methods over‐estimated recent migration rates; (ii) the coalescent‐based method (Migrate‐n) provided better estimates of recent migration rate than the disequilibrium‐based method (BayesAss); (iii) the coalescent‐based method did not accurately reflect long‐term genetic connectivity. Overall, our results highlight the problems with comparing coalescent and disequilibrium estimates to make inferences about the effects of recent landscape change on genetic connectivity among populations. We found that contrasting these 2 estimates to make inferences about genetic‐connectivity changes over time could lead to inaccurate conclusions.     

Direct Effects of Cattle on Grassland Birds in Canada

Effects of grazing on grassland birds are generally thought to be indirect, through alteration of vegetation structure; however, livestock can also affect nest survival directly through trampling and other disturbances (e.g., livestock‐induced abandonment). We extracted data on nest fates from 18 grazing studies conducted in Canada. We used these data to assess rates of nest destruction by cattle among 9 ecoregions and between seasonal and rotational grazing systems. Overall, few nests were destroyed by cattle (average 1.5% of 9132 nests). Nest destruction was positively correlated with grazing pressure (i.e., stocking rate or grazing intensity), but nest survival was higher in more heavily grazed areas for some species. Because rates of destruction of grassland bird nests by cattle are low in Canada, management efforts to reduce such destruction may not be of ecological or economic value in Canada. Efectos Directos del Ganado sobre las Aves de Pastizales en Canadá