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Signals of escalating aggressive motivation in birdsong
Škvařilová, Anežka ; Petrusková, Tereza (advisor) ; Schneiderová, Irena (referee)
Singing plays a vital role not only in the communication of songbirds, but it also holds a variety of information about the singer. For example, singing can reveal a singer's age, physical ability, or individuality. At the same time, it can tell how willing the singer is to attack. For this purpose, males use signals of escalating aggression, which they apply primarily during territory defence, using them to inform each other of their motivation to fight. There are several characteristics in birdsong that are considered to be signals of escalating aggression. These include song type switching, song type matching, overlapping, song length, song rate and soft song. It appears that the nature of conflict signalling is highly variable across species. This bachelor thesis analyses these singing characteristics in depth and evaluates, according to established criteria, whether they can be considered as signals of conflict escalation in different songbird species. Keywords: signals of conflict escalation, aggressive behaviour, territorial interaction, playback, singing characteristics, attack
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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 in two species of ground squirrels Spermophilus citellus and S. taurensis (Sciuridae; Rodentia).
Schneiderová, Irena ; Vohralík, Vladimír (advisor) ; Petrusková, Tereza (referee)
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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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 ; 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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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 accommodation in howling of grey wolf (Canis lupus)
Schindlerová, Loretta ; Schneiderová, Irena (advisor) ; Linhart, Pavel (referee)
Vocal accommodation is the adjustment made by interlocutors while communicating, such as the adjustment of vocal pitch (i.e. the fundamental frequency) to match that of the other speaker. This behaviour can strengthen social bonds and has been predominantly studied in humans but recently also in the field of animal communication. Wolves are highly social animals and their howls - solos, duets, and choruses - are rich in information, yet vocal accommodation has not been studied in this species. Using a number of approaches, we explore whether grey wolves (Canis lupus) vocally accommodate to other wolves in duet howls by altering their howl contours to either converge to or diverge from another wolf's howl. To this aim we assessed the differences in the variables of the fundamental frequency and the contour of fundamental frequency using linear mixed models, Euclidean distance and dynamic time warping as metrics. Of the multiple analyses that we performed, one analysis identified significant differences between solo and duet howls, while another analysis indicated that duet howls within dyads were more similar than duet howls from different dyads. Our results point to the need for further exploration of the sources of variability and the role of context in order to confirm the existence of vocal...
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Voice and its modulation in human mate choice
Vobecká, Tereza ; Třebický, Vít (advisor) ; Schneiderová, Irena (referee)
1 Abstract Vocal communication is one of the primary means of communication in humans. Information from utterances not providedsolely by speech but also by their acoustic properties (e.g. voice pitch). People tend to associate different acoustic parameters of voice with specific human characteristics, such as physical traits such as body size, sex or personality traits such as dominance or attractiveness. Human voice is dynamic, and it is modulated depending on the inner state of the speaker and external circumstances. For example, the modulation of speaker's voice may be caused by their emotional state or depend on the person they are talking to. This work aims to summarize and review existing literature about the modulation of acoustic parameters of the voice and its effect on perception of others in mate-choice context. Key words acoustics, attractiveness, non-verbal vocalization, fundamental frequency, preferences
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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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Utilization and potential of individual acoustic monitoring in birds
Kouřil, Jan ; Petrusková, Tereza (advisor) ; Schneiderová, Irena (referee)
Animal monitoring is a key tool for many disciplines and can be done many ways. One of them is acoustic monitoring, which is advantageous mainly for a research of animals with strong vocalisation. Bird vocalisations are one of the most conspicuous. It can carry many information about the singer, and identity is one of them. Vocal individuality has been documented in many bird species and it is considered as a widespread phenomenon. In species, where vocalisation is individually unique and also stable over time, it allows us to track and identify individuals from recordings of their vocalisations only, i.e. by individual acoustic monitoring. Using this approach, many ecological data (abundance, survival rate, etc.) might be successfully collected. So far, it was used mainly in species with simple, loud vocalisations which was difficult to monitor by commonly used physical marking due a dense habitats, cryptic coloration, low density of occurrence, etc. Most often, it used for owls, although the vocal individuality, or even its temporal stability, was documented in much more avian species. Compared to commonly used methods, individual acoustic monitoring is not used very often. However, it can be assumed that with the development an improvement of analytical methods, it will become a commonly used...
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