Opportunistic predator like the long-eared owl is able to respond to population fluctuations of its main prey. The composition of the winter diet of this owl species was investigated during the period of 13 winters (1992-2000, 2006-2011) in agricultural areas in Slovakia. In total, we found 23 mammal species and 33 bird species (H′ = 0.82) in pellets. The frequency of the dominant prey species, the common vole, varied from 57.7% to 92.4%. Our data show that the abundance of the common vole: (i) had biggest impact on the food niche breadth of the long-eared owl; (ii) when in decline, it was significantly compensated by the increase in the amount of 15 other accessory species (subject to the specific diet offered during the study winters); (iii) was positively correlated with the number of owls in the winter-roost, which varied during the 13 studied winters.

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Based on pellets analysis from five localities in south western Slovakia (Malá Mužla, Malé Ripňany, Obid, Opatovský Sokolec and Tešedíkovo), we studied the diet composition of Barn Owl (Tyto alba) in intensively cultivated agricultural lands. A total of 6218 specimens of prey, 17 mammalian and 7 bird species were identified. The main prey species found in all food samples was the Common Vole (Microtus arvalis), varying between 56 % and 67 %. The proportion of synanthropic species (Rattus norvegicus, Passer domesticus) and species inhabiting agricultural landscapes (Crocidura leucodon, Crocidura suaveolens, Mus sp.) increases in localities with a lower ratio of the Common Vole. The results suggest land use affects the diet of Barn Owls, confirming conclusions which have been drawn in previous studies. From faunistic point of view, discovering the Pannonian Root Vole (Microtus oeconomus mehelyi) in the diet from Malá Mužla was important.

Landfills, old and abandoned mines, industrial sites, heaps, sludge ponds and other sources of pollution represent environmental threats and are characterized as chemical time bombs. This work is focused on the evaluation of soil contamination by risk elements using various indices (geoaccumulation index—Igeo, enrichment factor—EF, contamination factor—Cif and degree of contamination—Cd). These selected agrarian problem areas are located in Slovakia, especially in the air pollution field of landfills consisting of power plant fly ash, tannery and footwear wastes, leachate (lúženec), iron ore slag, waste from metallurgy and sludge ponds in which coal sludge waste is deposited and waste from ore treatment. Nine research sites in the agrarian region of Slovak Republic were monitored. Ten risk elements (Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb, Cd and Hg) and pH/H2O were included in this study and were determined in surface soils (of 0.05 m to 0.15 m) using atomic absorption spectrometry (AAS). Our study showed the highest exceedance of the limit values of risk elements in the order Ni (51.85 times) > Co (25.47 times) > Cd (13.70 times) > Cu (12.78 times) > Cr (8.37 times) > Fe (8.26 times) > Hg (7.94 times) > Zn (5.71 times) > Pb (4.63 times). The content of risk elements increased based on the average values of Igeo in the order of Cr < Hg < Zn < Pb < Ni < Cu < Cd. Igeo values for cadmium indicated mild-to-extreme contamination at all sites. We found the most significant enrichment in the order of Cd > Cu > Pb > Ni > Zn > Hg > Cr. EF values for cadmium indicated extremely high enrichment; the Cif and Cd values indicated a very high degree of soil contamination near the nickel smelter landfill, an industrial metallurgical plant and old but active mines. The studied areas pose a serious danger not only to the soil but also to groundwater and biota due to the prevailing low soil reaction, which increases the mobility of toxic elements. The study provides important results for the development of effective strategies for the control and remediation of endangered areas.

The causal chain of parasite–host–environment interactions, the so-called ‘dual parasite environment’, makes studying parasites more complicated than other wild organisms. A sample of 65 282 fleas taken from 336 different locations were analysed for changes in the distribution, diversity and compensation of flea communities found on small mammals along an elevational diversity gradient ranging from the Pannonian Plain to the base of the Carpathian summits. The fleas were divided into four groups, which were derived from changes in abundance and occurrence determined from cluster analysis. They are (1) flea species whose range seems unrelated to any change in elevation; (2) species that avoid high altitudes; (3) a group that can be subdivided into two types: (i) host-specific fleas and (ii) mountains species and (4) species opting for high altitudes on the gradient or preferring lower to middle elevations below 1000 m. Our study showed a unimodal pattern of flea diversity along the elevational gradient. It indicated that seasonality significantly conditions changes in biodiversity and patterns of spatial change along the elevational gradient, with specific flea species influenced by their host, while the impact of environmental conditions is more pronounced in opportunistic flea species.

The distribution of the endangered glacial relict subspecies, the Pannonian root vole Alexandromys oeconomus mehelyi Éhik, 1928, is restricted to scattered localities in south-western Slovakia, which belong to the north-eastern zone of its range. Human-induced changes and fragmentation of the landscape have led to the gradual loss of suitable habitats and threaten its long-term survival. The study area in the Danubian Lowland is characterised by small habitat fragments and temporal fluctuations of the habitat area. Root voles were sampled at nine sites to study the level of genetic variability and structure of local subpopulations by scoring 13 microsatellite loci in 69 individuals. Genetic differentiation varied amongst local populations and we did not find a significant isolation-by-distance pattern. Bayesian clustering analysis suggested that dispersal effectively prevents marked genetic subdivision between studied habitat fragments. Significant pairwise differentiation between some subpopulations, however, may be the result of putatively suppressed gene flow. Low genetic diversity in the recent populations probably reflects the isolated location of the study area in the agricultural landscape, suggesting that long-term survival may not be assured. In order to maintain genetic diversity, it is essential to preserve (or even restore) habitats and ensure the possibility of gene flow; habitat protection is, therefore, recommended. Continuous assessment is necessary for effective conservation management and to predict the long-term survival chances of the Pannonian root vole in the study area.

Food supply in the nesting territories of species has a key role to the species diet composition and their breeding success. Red-footed falcon (Falco vespertinus) preys predominantly on larger insect species with a supplementary portion of smaller vertebrates. In the breeding periods 2014 and 2016 their food supply, focusing on Orthoptera, Mantodea, Rodentia and Eulipotyphla, was analysed at five historical nesting sites of the species in Slovakia. Preference for these prey groups in the diet was also studied at the last active nesting site in this country. Overall we recorded 45 Orthoptera species (of which 23 species are known as the food of the red-footed falcon), one species of Mantodea, 10 species of Rodentia (of which 2 species are known as the food of the red-footed falcon) and 5 species of the Eulipotyphla order in the food supply. With regard to the availability of the falcons' preferred food, in both years the most suitable was the Tvrdošovce site, which continuously showed the greatest range and abundance of particular species. In the interannual comparison the insects showed lower variability in abundance than the small mammals. In 2014 the growth of the common vole (Microtus arvalis) population culminated and with the exception of a single site (Bodza) a slump in abundance was recorded in 2016. In comparing the diet composition with the food supply at the last Slovak breeding site Rusovce (Special Protection Area Sysľovské polia), we recorded significant preference for grasshopper Caliptamus italicus (in 2014), common vole (in 2016) and cricket Tettigonia viridissima (in both years) in the falcons' diet. They did not prey on the Apodemus sylvaticus species belonging among the abundant small mammal species in that locality. Conservation measures in the agricultural landscape are discussed in relation to homogeneous red-footed falcon breeding territories.Abstrakt: Potravná ponuka v hniezdnych teritóriách druhov hrá kľúčovú úlohu pre zloženie potravy druhov a ich hniezdny úspech. Sokol kobcovitý (Falco vespertinus) loví prevažne väčšie druhy hmyzu, dopĺňané menšími stavovcami. V hniezdnom období rokov 2014 a 2016 bola na piatich historických hniezdiskách druhu na Slovensku sledovaná jeho potravná ponuka so zameraním na Orthoptera, Mantodea, Rodentia a Eulipotyphla. Na poslednom aktívnom hniezdisku sa študovalo aj zastúpenie týchto skupín v potrave. Celkovo sme zaznamenali 45 druhov Orthoptera (z toho 23 druhov je známych ako potrava sokola kobcovitého), jeden druh Mantodea, 10 druhov Rodentia (z toho 2 druhy sú známe ako potrava sokola kobcovitého) a 5 druhov radu Eulipotyphla. Z hľadiska potravnej ponuky bola v oboch rokoch najvhodnejšia lokalita Tvrdošovce, ktorá kontinuálne vykazovala najvyššie druhové bohatstvo a abundanciu jednotlivých druhov. V medziročnom porovnaní hmyz vykazoval menšiu variabilitu početnosti ako drobné cicavce. V roku 2014 totiž vrcholila gradácia populácie hraboša poľného (Microtus arvalis), ktorá s výnim-kou jednej lokality (Bodza) zaznamenala v roku 2016 prepad po...