National Repository of Grey Literature 51 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Sonar design in Old World bats: patterns of specialisation
Staňková, Markéta ; Horáček, Ivan (advisor) ; Lučan, Radek (referee)
Echolocation ranks among key components of adaptive setting of bats. It enabled them to evolve a plethora of diverse foraging strategies and exploit an enormous spectrum of food resources for which they represent one of the most diversified groups of terrestrial mammals with a cosmopolitan distribution. Evolution of echolocation proceeded via responses to diverse constraints and factors, both intrinsic and extrinsic, that effect particular variables of echolocation biology. The present bachelor surveys, based on literary records, briefly some of these effects and their role upon structure of bat communities. I summarize basic characteristics of echolocation types, influence of Doppler shift, strategy and use of echolocation in different environments and adaptation against defensive abilities of a prey. Among other I provide an account of history and evolution of bat detectors, the instruments essentially improving current study of that topics. Keywords: Bats, echolocation, sonar, diversity, adaptation, Old World
History of Sorex araneus group in the western Palearctics (Mammalia, Soricidae)
Cestrová, Aneta ; Horáček, Ivan (advisor) ; Vohralík, Vladimír (referee)
The bachelor thesis reviews the literary data on the species group Sorex araneus, one of the most important component of the Holoarctic communities of small ground mammals. It provides a brief account of the life history patterns of the group (activity pattern, foraging strategy, reproduction) responding to demands of extremelly high energentic metabolism. The evolutionary setting of the group is characterized by a specific complex of sex chromosomes XX/XY1Y2, and enormous extent of chromosomal polymorphism due to multiple Robertsonain translocations producing a large number of chromosomal races with distinct combination of metacentric chromosomes. The interpretations on history of the group provided by molecular phylogenetics are compared with phylogenetic signals of the abundant fossil record of the group. Despite its richness (more than 300 fossil assemblages) the interpretation of fossil record is still confused and calls for a detailed re-examination. Key words: Sorex araneus, fossil record, phylogeography, Pleistocene, Palearctic
Concept of body in Old Norse literature
Novotná, Marie ; Komárek, Stanislav (advisor) ; Horáček, Ivan (referee) ; Starý, Jiří (referee)
This work attempts to outline concepts associated with body in the Old Norse literature. As the word for the body (líkamr) as well as the term for an incorporeal soul (sál) do not occur in the Old Norse literature until the translated Christian works and cannot therefore be used as markers, two areas closely connected with the concept of body have been chosen for the research: shifting of shape (hamr) and somatic expressions of emotions. In the first area, i.e. phenomena associated with shape-shifting, contexts of all (113) occurrences of radix ham- in the Old Norse literature are analysed in order to describe the semantical field of this root. Within the themes that have appeared in the material (i.e. shape-shifting related to flying, battle frenzy and magic), occurrences are ordered on an axis from those where the form (hamr) is considered to be holistic to those where just the form of body or soul is described. In this context, it is important to mention the proximity of man and animal in the Germanic environment, as shape-shifting is often related to an animal and thus points to the limits of human identity. In the second area, i.e. somatic expressions of emotions, we can also find cases where the mental and the physical area intersect and the boundaries between diseases and emotions are not...
Genus Sicista (Mammalia, Rodentia, Zapodidae) in the Western Palearctics: diversity, phylogeny and paleobiogeography.
Lišková, Tereza ; Horáček, Ivan (advisor) ; Vohralík, Vladimír (referee)
The bachelor thesis surveys literary data on taxonomy, distribution, phylogeny and range history of the genus Sicista, one of the least known clade of Palearctic rodents. The genus composes a monotypic family Sminthidae, a basal branch of the superfamily Dipodoidea recorded since the late Eocene. Fourteen recent species are currenty distinguished. Most of them colonize small vicariant ranges distributed from East Asia to Central Europe with peak of species diversity in Central Asia and Caucasus regions. Also two taxa occupying large ranges (S.betulina, S.subtilis) including eastern parts of Central Europe rank among the rarest local specis throughout most of their ranges. The European fossil record (more than 150 Quaternary sites) indicate quite a more extensive distribution covering diverse regions of the Western Europe during the Pleistocene and the early Holocene. Yet, the species identity of many fossil records remain doubtful due to quite indistinct morphological differences among particular species. The discrimination criteria and range history in Central Europe are discussed in details with particular attention to the fossil record available from the Czech Republic and Slovakia. Key words: Sicista, phylogeny, range history, diversity, taxonomy, Western Palearctics
Social behaviour and ecology of bats of the genus Pipisttrellus
Jahelková, Helena ; Horáček, Ivan (advisor) ; Řehák, Zdeněk (referee) ; Červený, Jaroslav (referee)
43 Summary of results of presented research Since discrimination of two cryptic species inside Pipistrellus pipistrellus s.l based on echolocation calls (Jones & van Parijs 1993), social calls (Barlow & Jones 1997), and molecular data (Barratt et al. 1997), the genus Pipistrellus have been studied intensively. The mainstream of my research were reproduction strategies and vocalization behaviour of Nathusius's pipistrelle (Pipistrellus nathusii). It is a small European insectivorous species, which is known for his migratory behaviour. The dominant mating system is resource-defence polygyny. Males vocalize during flight (songflight) and from entrances of their day roosts (sedentary display). Advertising calls occur during whole active season, but they considerable increase during mating season. Males show strong fidelity to their mating roosts whereas females are fixed to maternity colonies (Schmidt 1984, Rachwald 1992, Gerell-Lundberg & Gerell 1994, Furmankiewitz 2003, Petersons 2004). This species exhibits variability in mating behaviour in different countries, probably due to long- distance migrations. In Czech Republic, the species was considered to be rare and only sporadic indications of reproduction were found (Hanák & Gaisler 1976, Šefrová & Buřič 1998). Main research area of my study was in South...
Lagomorpha (Mammalia) of the Pliocene and Pleistocene of Europe: a revision of selected taxa
Čermák, Stanislav ; Horáček, Ivan (advisor) ; Sabol, Martin (referee) ; Benda, Petr (referee)
1 Lagomorpha (Mammalia) pliocénu a pleistocénu Evropy: revize vybraných taxonů Stanislav Čermák Předkládaná dizertační (uznaná jako rigorózní) práce se zabývá vybranými taxony fosilních zajícovců (starobylá konzervativní skupina býložravých savců) úseku spodního pliocénu až spodního pleistocénu (ruscin - bihar) Evropy. Technikami podrobné morfometrické analýzy (42 metrických, 14 nemetrických znaků) byl zpracován fosilní materiál (většinou nový nepublikovaný) dentálních a kraniálních pozůstatků rodů Psedobellatona, Ochotonoma, Ochotona a Hypolagus (N = 639) celkem z 38 lokalit území Česka, Slovenska, Maďarska a Ukrajiny reprezentující stratigrafický úsek spodní ruscin až svrchní bihar (MN 14 - Q2). Daná práce podává: (1) Ochotonidae - detailní revizi dosud komplexně nestudovaných taxonů pišťuch "skupiny Ochotona" spodního pliocénu (ruscin) východní a jihovýchodní Evropy (tj. taxonů Ochotona antiqua, Pseudobellatona, a Ochotonoma); v kontextu Česka a Slovenska revizi nálezů rodu Ochotona z pleistocénních (MN 17 - Q1) lokalit daného území, která podstatnou měrou rozšiřuje znalosti o těchto pišťuchách založené dosud na relativně nepočetných nálezech z lokalit Francie, Německa, Polska a Maďarska; (2) Leporidae - komplexní revizi rodu Hypolagus - stěžejního a dominantního rodu čeledi Leporidae pliocénu a...

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