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Distribution and abundance of wintering and breeding population of Mute Swan (\kur{Cygnus olor}) in the South Bohemia region
HNÍDKOVÁ, Lucie
This work evaluates quantity of the mute swan (Cygnus olor) in wintering grounds and nesting sites in southern Bohemia. The mute swan became the target species of the JOK 2020 Bird of the Year campaign. The aim of mapping the mute swan population in 2020 was to identify as much of its South Bohemian nesting and wintering population as possible. The census followed similar projects from previous years and it took place in a total of four terms. The most important of them was the third term, which involved the nesting and leading of the young swans. A total of 1358 locations were inspected. In the first term, i.e., during the count in wintering grounds, 387 swans were recorded in 184 locations. During nesting, i.e., in the second and third terms, a total of 1230 locations were inspected, of which 368 (29.92 %) were occupied. There were 162 nesting pairs in 159 locations. In the third term separately, a total of 1003 locations were inspected, 1563 individuals at 221 locations were recorded, 96 pairs with a total of 434 young were present. During the August after-nesting count, 666 locations were inspected, and 1284 swans were recorded at 122 locations. Nesting swans most often occurred in habitats with vegetation area over 25 %.
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Freshwater mussels (Unionidae) in CITES
HNÍDKOVÁ, Lucie
This work assesses the international trade in the Unionidae species from 1987 to 2015. The species of the Unionidae family are listed in the CITES International Convention. Most of them (26 species from 12 genera) are included in Appendix I of CITES, only three species (Cyprogenia aberti, Pleurobema clava and Epioblasma torulosa rangiana) are listed in Annex II. They are mainly US endemic, or USA and Canada. Most of them occur only in one or two rivers, often only in a certain section of the river. These species are host specific. Some of them are bound to only one genus or species of fish. From a trading point of view, Unionidae were traded in the following forms: shells, carved shells, derivatives, live individuals and specimens. The species Dromus dromas, Pleurobema clava, Cyprogenia aberti and Conradilla caelata were traded the most. The most common was the trade in the shells of individuals whose origin dates from before the inclusion of the species Unionidae to CITES for commercial purposes. These individuals were mostly of an unknown provenance and if the country of origin was stated, it was United States of America. The places, from which they were exported most were Hongong and the Philippines. The most frequent place of import were the US.
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