Hybridization is a significant threat for endangered species and could potentially even lead to their extinction. This concern applies to the globally vulnerable Greater Spotted Eagle Aquila clanga, a species that co-occurs, and potentially interbreeds, with the more common Lesser Spotted Eagle Aquila pomarina in a vast area of Eastern Europe. We applied single nucleotide polymorphism (SNP) and microsatellite markers in order to study hybridization and introgression in 14 European spotted eagle populations. We detected hybridization and/or introgression in all studied sympatric populations. In most regions, hybridization took place prevalently between A. pomarina males and A. clanga females, with introgression to the more common A. pomarina. However, such a pattern was not as obvious in regions where A. clanga is still numerous. In the course of 16 years of genetic monitoring of a mixed population in Estonia, we observed the abandonment of A. clanga breeding territories and the replacement of A. clanga pairs by A. pomarina, whereby on several occasions hybridization was an intermediate step before the disappearance of A. clanga. Although the total number of Estonian A. clanga ¥ A. pomarina pairs was twice as high as that of A. clanga pairs, the number of pairs recorded yearly were approximately equal, which suggests a higher turnover rate in interbreeding pairs. This study shows that interspecific introgressive hybridization occurs rather frequently in a hybrid zone at least 1700-km wide: it poses an additional threat for the vulnerable A. clanga, and may contribute to the extinction of its populations.

S. uralensis is a typical silvatic species, specialized for this life style through its biology and diet. Synanthropization is a rare phenomenon in this species, reflected in the changes of diet and hunting strategies, adapting to the characteristics of the urban environment. Between November 22, 1993 and June 2, 1994, an individual of the Ural Owl was observed 39 times in the urban areas of Košice city. The examination of the pellets revealed that the Ural Owl specialized in hunting Streptopelia decaocto (76.7%) and Columba livia f. domestica (13.4%). These results were confirmed by observations of S. uralensis hunting S. decaocto. This discovery is the first direct evidence of S. uralensis diet adaptation to S. decaocto and feral C. livia f. domestica in Slovakia.Abstrakt: S. uralensis je typickým obyvateľom lesov, k čomu je prispôsobená aj jeho biológia a potravné zloženie. Proces synantropizácie u tohto druhu je výnimočným javom, s čím súvisí aj zmena jeho potravy a spôsob lovu vzhľadom na špecifické mestské prostredie. V čase od 22. 11. 1993 do 2. 6. 1994 v mestskom prostredí mesta Košice bol pozorovaný jeden ex. 39 krát. Analýza vývržkov potvrdila v tomto prípade potravnú špecializáciu S. uralensis na Streptopelia decaocto (76,7 %) a Columba livia f. domestica (13,4 %). Výsledky sa potvrdili aj priamymi pozorovaniami, kedy S. uralensis ulovili jedince S. decaocto. Toto zistenie predstavuje prvý doklad potravnej špecializácie S. uralensis na S. decaocto a mestské holuby na Slovensku.Key words: urban habitat, Eurasian Collared Dove, Streptopelia decaocto, diet, urbanization Miroslav Dravecký, Rovníková 8, SK-040 12 Košice, Slovakia. E-mail: dravecky.miroslav @mail.t-com.sk. Ján Obuch, Comenius University, Botanical garden, SK-038 15 Blatnica, Slovakia. E-mail: obuch@rec.uniba.sk. Acknowledgment:We thank to our colleagues J. Lipták, J. Mihók, R. Reistetter and S. Pačenovský who provided us with data on Ural Owls occurrence from the Košice city. We also thank to M. Uhrin and Š. Danko for their valuable comments to this article. IntroductionThe Ural Owl is a common inhabitant of the forest habitats in the eastern parts of Slovakia, comprising approximately 1000 breeding pairs. The western boundary of its range is extending much further than supposed in the past and reaches beyond Slovakia into the Moravian-Silesian Beskids (Danko et al. 2002). The Ural Owl is a resident species, migrating to lowland areas only during harsh winters. This species inhabits broad-leaved, mixed and rarely also coniferous forests in the Carpathian Mountains. In the years of overbreeding, the winter range of our population is expanding. Along with the invasions from the North, the expansion accounts for ever more frequent winter sightings of the Ural Owl in the Slovak lowlands (Danube and East-Slovak lowlands) or in rural and urban areas of villages and larger towns (Mošanský, Hudec, Matoušek, Šťastný in Hudec 1983). The knowledge on the distribution of S. uralensis in the town of Košice and its surroundings was summarized ...

Diet of the Lesser Spotted Eagle (Aquila pomarina) in Slovakia In the period 1964-2007, data on 1472 ex. of prey was acquired from whole Slovakia. It was confirmed that the location of the breeding population on the foothills and mountains of the Carpathian Arc has a cardinal contribution to diet diversity. The breeding sites and hunting-grounds were found from 100 to 1 000 meters above sea level. The dominant part of the diet created mammalian species (88.11 %, 19 species and Sorex sp., Apodemus sp., undetermined Artiodactyla). Birds were less represented but with higher diversity of species (6.25 %, 24 species and Columba sp., undetermined Passeriformes). In comparison with birds, the share of Amphibia, Reptilia and Pisces together (4.89 %, 5 species and Rana sp., Lacerta sp., undetermined Serpentes and Reptilia) was lower. Pisces constituted only 0.007 % with 1 ex. of prey species Cyprinus carpio. Evertebrata constituted 0.75 % and species from orders Orthoptera, Coleoptera, and Diptera were found. The dominant prey of A. pomarina in Slovakia was Microtus arvalis (69.57 %), followed by Arvicola terrestris (5.16 %) and Microtus agrestis (3.94 %) constituting significantly lower proportion. These three species from the category small rodents composed 75.67 % of diet. Less abundant species in range 2.24-1.00 % were Talpa europaea (2.31 %), Rana temporaria (2.24 %), Cricetus cricetus (1.70 %), Phasianus colchicus (1.15 %), and Lepus europaeus (1.09 %). In lesser extent (1.0-0.5 %) also other mammalian species such as Apodemus flavicollis (0.88 %) and Mustela nivalis (0.88 %) were represented. The most frequently encountered birds were Galliformes such as P. colchicus (1.15 %), Gallus gallus domesticus (0.48 %), and Coturnix coturnix (0.54 %). Other more abundant prey bird species were Alauda arvensis (0.48 %), Columba sp. (0.48 %), and Crex crex (0.34 %). From the class Reptilia relatively high share of Anguis fragilis (0.95 %) and Lacerta sp. (0.68 %; most probably Lacerta agilis) were recorded. Other species with representation lower than 0.3 % were a random prey of A. pomarina.

Unlike chlorination fluorination of ammine complexes of platinum(IV) in aqueous solution does not lead to haloamido complexes. Instead, the triammine complexes [Pt(NH3)3Cl3]Cl and [Pt(NH3)3(NCl2)2Cl]Cl yield no definite main product, and the tetrammine and pentammine complexes trans-[Pt(NH3)4C12]C12, [Pt(NH3)4(NCl2)Cl]Cl2, [Pt(NH3)5Cl]Cl3, and [Pt(NH3)5(OH)]Cl3 form the sparingly soluble complex trans -[Pt (NH3 )4C12] (H2F3 )2 • 2 H-20 as the main product.

Acknowledgement:The authors would like to thank to Ladislav Bohačík, Andrej Dúbravský, Richard Galáš, Stanislav Harvančík, Dušan Karaska, Ján Kicko, Miroslav Lehocký, Metod Macek, Jozef Mihók, Vladimír Pečeňák, Leonidas Prešinský, Radovan Reťkovský, Slávka Siryová, Ladislav Šnírer, Karol Šotnár, Oldřich Šreibr, Josef Vrána and Peter Vrlík for co-operation and information on productive Lesser Spotted Eagle pairs, which fledged 2 young without human intervention.