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Seasonal variation of the territorial behaviour of the European beaver (Castor fiber L.).
Kadlecová, Hana ; Horáček, Ivan (advisor) ; Červený, Jaroslav (referee)
The presented thesis deals with the temporal and spatial changes in activity of the European beaver (Castor fiber L.) during different seasons. Basic dataset was obtained by continuous telemetric monitoring of selected individuals in years 2008 and 2009 in two different geographical areas, namely in the Bohemian forest and in southern Moravia. The scope of the thesis was to record, evaluate and interpret the behavior of European beaver during the year. I focused myself especially on the beginning and end of activity in relation to incidence of sunrise and sunset, duration of stay in the field, changes in the size of actively-used area and time-duration and length of the movement. In cases where there were more active individuals monitored within the studied area, I also watched for their mutual interaction. In statistical analysis of gained data I also took into account the sex and age of the individuals. Beaver's behavior varies during the year. They are most active in spring and autumn, while in winter their activity decreases significantly. This observation is valid not only for the time duration and length of movement trajectories, but also for the size of actively-used area. The beginning of activity is strongly correlated with the sunset, while the end does not show any correlation with...
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Dental phenotype variation in voles during the present glacial cycle
Putalová, Tereza ; Horáček, Ivan (advisor) ; Kuneš, Petr (referee)
The phenotype dynamics of arvicolid rodents during the terminal stages of the Vistualian glacial and the earliest Holocene was investigated with aid of a detailed morphometric analyses of extensive dental material from three sedimentary series of that age. The particular attention was paid to the record from a section in Býčí skála cave, Moravian karst, which demonstrated details of the Pleistocene/Holocene transition (12.4-8.4 ky BP) with extraordinary resolution. It revealed that dramatic rearrangements in community structure were accompanied by significant rearrangements of the phenotype dynamics in all arvicolid species. Despite some trends specific for particular species, some common features were identified as well. One of them was a rapid turnover in phenotype structure by the end of Younger Dryas, at time of the Preboreal event. (11.7-11 ky BP), the other was associated with the extensive shifts in community structure and habitat diversity at terminal stage of the Preboreal (9.7-9.3 ky). The core arvicolid species of Preboreal communities, Clethrionomys glareolus, Microtus arvalis, M.agrestis and Arvicola terrestris, exhibited repeated fluctuations during that stage (ll-9,3 ky BP) both in abundance and phenotype characteristics, supposedly related to serial invasion events during that time....
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Small mammals in diet of barn owl in the Eastern Meditarranean
Šindelář, Jiří ; Horáček, Ivan (advisor) ; Anděra, Miloš (referee)
The extensive material of skeletal remains of mammals from a diet of barn owl in the eastern Mediterranean has been processed and evaluated with different techniques of chorological and morphometric analysis. At least 8400 individuals of 45 species of insectivores, rodents and bats were found in our total collection of samples, which represents a significant portion of fauna of the region. We have evaluated a chorological composition of the taphocoenoses and the interregional differences, manifested primarily by differences in the representation of satellite and accessory elements. We found a highly significant impoverishment of the isolated island taphocenoses (Cyprus, Karpathos, partly on Crete), where Cricetidae, Arvicolidae, C. leucodon etc. are missing. On the other hand the essential part of the dominance structure takes up the Rattus rattus, which acts here as an invasive species, significantly more successful than in the ragged continental contexts. The species diversity of the examined samples is positively correlated with the geographic latitude (taphocenoses of the northern regions are significantly richer) and negatively with the island effect and the degree of aridization. The morphometric analysis of the three most abundant species of Soricidae within the studied region showed...
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The ecological and ethological significance of felid coat patterns (Felidae)
Jaroš, Filip ; Komárek, Stanislav (advisor) ; Horáček, Ivan (referee) ; Weber, Andreas (referee)
The presented work investigates various theories about the significance of felid coat patterns. Most of the hypotheses are based on the theory of adaptive function of animal colouration. As regards felids, it is generally believed that the coat pattern has the function of aggressive resemblance. Early testimonies about cryptic properties of colouration of cats are summarized to provide the historical perspective of the problem. Other putative adaptive functions of patterns are investigated (intraspecific communication, thermoregulation) and close attention is paid to the option that the spotted coat of the leopard (Panthera pardus) serves as a cue for recognition from the perspective of prey. In the next stage, some of the hypotheses are tested by statistical means. The problem is simplified into search for association between a given category of a coat pattern (e.g. spots, stripes) and usual habitat of felid species (e.g. forest, grassland). Pagel's test for correlated changes is employed to account for phylogenetic relationships. In addition to broadly acknowledged hypotheses, the validity of proposition that juvenile coat patterns have the function of protective resemblance is tested. Finally, the problem of colouration of felids is linked to broader context of theoretical biology. Apart from prevailing...
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Racoon dog (Nyctereutes procyonides) in Central Europe: history of range expansion and current state of knowledge
Pyšková, Klára ; Horáček, Ivan (advisor) ; Vohralík, Vladimír (referee)
The thesis is about the raccoon dog (Nyctereutes procyonoides), a canid invasive in a large part of Europe. It describes its distribution in native and invaded range, the history of colonisation, ecology and social behaviour, as well as its impact in the invaded range. Available knowledge is summarized, with main focus on central Europe. The native distribution range of the species is in eastern Asia. The animals were first brought to the European part of the former Soviet Union in the first half of 20th century for breeding at fur farms, and later being released into the wild for hunting. The raccoon dog colonised 1,4 million km2 over the next 50 years, and became an established carnivore common in many European countries. A number of factors influenced the successful invasion; an opportunistic feeding strategy and high habitat adaptability; repeated and numerous introductions over a long period of time, resulting in a high genetic variability; the ability to hibernate; low numbers of predators; the tendency to wander, sometimes to quite distant areas; and high intraspecific tolerance. The environmental and economic impact of raccoon dog seems to be rather low, and the most dangerous aspect of its invasion is the transmision of infectious diseases, mainly rabies.
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