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Boar vocalizations and their potential role in sexual selection
Roreitnerová, Daniela ; Linhart, Pavel (advisor) ; Schneiderová, Irena (referee)
The aim of this research was to gather existing knowledge about vocalizations of boars and their potential role in sexual selection. Few studies mainly from the 70s and 80s of the last century suggest that the so-called love song, emitted by males during courtship, could act as a stimulant that triggers mating. However, I did not find any evidence that boars significantly use calls in fights. Most studies deal with pig vocalization in a different context. For this reason, I tried to look at the studies of pig relatives - even-toed ungulates - to better evaluate the potential role of boar vocalizations in sexual selection. In their case, the influence of the calls on the sexual behavior of females and competing males was reported. It is possible to conclude that the role of boar vocalization is probably not that important as in red deers, for example, because boars use calls in short range communication. On the other hand, stimulatory effect on females was found in other species too. Further studies are needed to understand possible function of boar vocalizations that could be used for example in pig breeding to improve the effectiveness of artificial insemination of sows. Powered by TCPDF (www.tcpdf.org)
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Vocal ontogenesis in grey parrots in comparison to humans
Roubalová, Tereza ; Lindová, Jitka (advisor) ; Schneiderová, Irena (referee)
Human speech is considered to be unique means of communication. The beginnings of human vocalization, which develops into the speech, however, have some patterns or principles which can also be found in animal communication. It has been discovered that there are similarities between humans and animals in terms of social organization, neural control, cognition and function of vocal signals. Moreover, it seems that birds, parrots specifically, have closer parallels with humans in these respects than with other primates. Vocal ontogeny was, however, at least in parrots, investigated only marginally. Therefore it has become the subject of this study. African grey parrots (Psittacus erithacus) show a wide range of cognitive abilities and are thus suitable species for comparison with humans. The aim of this study was to map the early vocal development of African grey parrots until age of 11 weeks. Then it was possible to compare it theoretically with the early vocal development of children. The repertoire was mapped using video recordings of four fledglings of feral African grey parrots, which are in possession of FHS UK Prague. The recordings were analysed acoustically and visually with audio software Sound Forge Pro 11 and Sound Forge Audio Studio 10. After identifying the repertoire we used stage...
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Acoustic communication and its variability in selected populations of ground squirrels of the genus Spermophilus
Schneiderová, Irena
Acoustic communication and its variability in selected populations of ground squirrels of the genus Spermophilus (abstract) Irena Schneiderová; Department of Zoology, Faculty of Science, Charles University in Prague The thesis deals with vocalizations produced by Eurasian ground squirrels of the genus Spermophilus. It is mainly focused on inter-species and intra-species variability in acoustic structure of alarm calls which are emitted in presence of predators. The major part of the thesis deals with intra-species variability in acoustic structure of the alarm calls in five Eurasian ground squirrels, Spermophilus citellus, S. taurensis, S. xanthoprymnus, S. suslicus and S. fulvus. It has been confirmed that the alarm calls of these ground squirrels show a high level of species specificity. The thesis further describes another vocalizations produced by three Eurasian ground squirrel species, Spermophilus suslicus, S. citellus and S. fulvus., and shows that with the exception of the alarm calls, vocal repertoires of these three ground squirrels are remarkably similar. The last part of the thesis deals with individual distinctiveness of the alarm calls of three Eurasian ground squirrels, Spermophilus citellus, S. taurensis and S. xanthoprymnus. It has been shown that the alarm calls of these species have a...
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Bioacoustics in frogs
Karochová, Lucie ; Šandera, Martin (advisor) ; Schneiderová, Irena (referee)
This thesis is focused on bioacoustics in frogs. The purpose was to compare known informations about vocalization types, influence of sexual selection on males call, chorusing behavior and influence of predation. Bioacoustics research was carried on many frog species from different part of world, with most experiments being carried on neotropical frogs, specifically Physalaemus pustolosus. Acoustics communication is a wide-spread phenomenon across the animal kingdom. The theme of bioacoustics is studied quite extensively. The most studies is focused on birds or mammals, and the study of frogs, especially the European species, is poorly known. The influence of sexual selection on males vocalization is well known, while research in other evolutionary principles such as the effect of predator is studied only marginally. Research on new types of frogs tend to focus on the description of vocalization types that occur in a given species. In addition to in detail are studied individual voice parameters such as frequency or intensity and chorusing frogs are determined mainly by call-timing or synchronization. Newly was discovered ability of some frogs generate ultrasonic harmonies and surprising discovery was female vocalization as well. Generalization of facts is quite difficult because of the lack of...
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Acoustic communication and its variability in selected populations of ground squirrels of the genus Spermophilus
Schneiderová, Irena ; Vohralík, Vladimír (advisor) ; Sedláček, František (referee) ; Špinka, Marek (referee)
The thesis deals with vocalizations produced by Eurasian ground squirrels of the genus Spermophilus. It is mainly focused on inter-species and intra-species variability in acoustic structure of alarm calls which are emitted in presence of predators.The major part of the thesis deals with intra-species variability in acoustic structure of the alarm calls in five Eurasian ground squirrels, Spermophilus citellus, S. taurensis, S. xanthoprymnus, S. suslicus and S. fulvus. It has been confirmed that the alarm calls of these ground squirrels show a high level of species specificity. The thesis further describes another vocalizations produced by three Eurasian ground squirrel species, Spermophilus suslicus, S. citellus and S. fulvus, and shows that with the exception of the alarm calls, vocal repertoires of these three ground squirrels are remarkably similar. The last part of the thesis deals with individual distinctiveness of the alarm calls of three Eurasian ground squirrels, Spermophilus citellus, S. taurensis and S. xanthoprymnus. It has been shown that the alarm calls of these species have a significant potential to encode information about caller identity.
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Acoustic communication in two species of ground squirrels Spermophilus citellus and S. taurensis (Sciuridae; Rodentia).
Schneiderová, Irena ; Petrusková, Tereza (referee) ; Vohralík, Vladimír (advisor)
6 ABSTRACT Since now, acoustic communication and alarm calls of European ground squirrel and the recently described S. taurensis have been poorly studied. Aim of this study is to make first steps in studying and understanding their acoustic communication and alarm calls. It was found, that the European ground squirrel produces 6 vocal (growl, rapid growl, scream, squeak, chirp, whistle) and 1 nonvocal (tooth chatter) sounds. These sounds are produced when sousliks are directly threatened by predator or during their social contacts. The alarm call of European ground squirrel as well as of S. taurensis is the whistle. It usually consists of two different elements, which can be fused, overlapped in time or separated by short interval. The first element has a constant frequency, while the second one has little frequency modulation. In some cases, one of these elements can be missing. The study reveals individual variation in the alarm calls in both species. Sexual differences in alarm calls of S. taurensis were found. Keywords: Spermophilus citellus, Spermophilus taurensis, Sciuridae, ground squirrel, antipredator behaviour, acoustic communication, vocalization, vocal repertoire, alarm call.
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