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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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Effect of alarm call on tits' behavior on feeder
Lipanská, Barbora ; Fuchs, Roman (advisor) ; Petrusková, Tereza (referee)
LIPANSKÁ, B. 2011: Effect of alarm calls on tit's behavior on feeder. MSc Thesis. Faculty of Science, Charles University in Prague. Alarm calls of the Great tit (Parus major) used in the context of ground-predators or perching-raptors consist of high-frequency tonal syllables and of series of churring syllables with broad-frequency range. The function of some acoustical parametres of these complex calls was tested in playback experiment on feeder. As the most effective appeared to be alarm calling of two birds simultaneously. More important for warning function of the calls were broad-frequency range syllables. The length of series of these syllables had an opposite impact than in some north-American chickadees (genus Poecile). The Blue tit (Cyanistes caeruleus) responds to Great tit's alarm calls, but its reactions are weaker. This difference can be caused by its lower competition ability against the Great tit. Key words: antipredation behavior, alarm calls, tits, playback experiment
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Geographical variation of localisation in vertebrates
Cinerová, Michaela ; Petrusková, Tereza (advisor) ; Turčoková, Lucia (referee)
Sound expressing is common for a big amount of animal species, mostly when communicating with individuals of their own or other species. Acoustic communication can be used especially in situations or in the environment where an individual does not see a signal receiver well (confusing environment, at night or long distance). It's well-known that the individual species have their own characteristic acoustic expressions. However, these can differ also within the species itself, either in time or in space. This study is concerned just with variability of inter-species vocal communication of all vertebrates in space. Its purpose is to map at which animal species vocalization vary in space. Furthermore, it deals with searching for causes of origin of this variability, such as genetic differences among particular groups of populations, environmental and learning effects etc. within various animal species. In the last part, it tries to answer the question whether the spatial variability of acoustic signals could influence separation of new species and thus have evolutionary consequences.
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The function and variability of song in two interacting nightingale species
Souriau, Abel ; Petrusková, Tereza (advisor) ; Kipper, Silke (referee) ; Linhart, Pavel (referee)
- ABSTRACT - The melodious and complex song of nightingales is a well-established model in studies focussing on the development and function of birdsong. Moreover, two sister species: the thrush nightingale (Luscinia luscinia) and the common nightingale (L. megarhynchos), meet in a recent secondary contact zone in Central Europe, in which their close ecological preference result in competitive interactions and interspecific hybridization. In sympatry, thrush nightingale males often replace part or all of their song repertoires with the songs of the common nightingale, a phenomenon called "mixed singing", while the opposite tendency has not been observed. Understanding the reasons behind the occurrence of thrush nightingale mixed singing, as well as exploring the similarities and difference in song structure between the two species, were the main aims of this thesis. In the first chapter, we tested the role of mixed singing on breeding common nightingale males and revealed its possible function in mediating territorial conflicts. Such advantage might be adaptive as it could help balance the potential costs of heterospecific song copying, and therefore help maintain the asymmetric song convergence between those species. The second chapter aims to explore further the function of thrush nightingale song...
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Yellowhammer as a model species for studies on passerine dialects
Diblíková, Lucie ; Petrusková, Tereza (advisor) ; Procházka, Petr (referee)
Even though birdsongs and bird dialects have been subject to considerably intense scientific research, the domain of bird dialects is still worth attention of scientists. There is a large number of hypotheses about the emergence of bird dialects which separately or combined explain their origin. Dialects can be classified on the basis of the structure of a birdsong which they are related to or according to a geographical scale (micro and macrodialects). Research on bird dialects belongs to such type of studies that require great amount of data and thus large amount of time and finance is needed. Nonetheless, this obstacle can be avoided by involving general public into the research, however choosing a suitable model species is necessary. Yellowhammer (Emberiza citrinella), which was chosen in this study, is undoubtedly a convenient species for its common occurrence and distinguishable birdsong. Yellowhammer males sing during a large part of the season and their dialects can be easily recognized. Moreover, some scientists differentiate between macrodialects, that should be divided across western and eastern Europe, and could be used to make the research more attractive for general public. Till now yellowhammer dialects have been thoroughly explored in Denmark and in some parts of Germany, but in other...
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Testing of functions of song types and specific structures of tree pipit song
Kinštová, Anna ; Petrusková, Tereza (advisor) ; Riegert, Jan (referee)
4 Abstract Bird song is usually considered to have two primary functions; attract females and repels males. Hence, song features can be an indicator of male quality or aggressive motivation. It has been suggested that one of those features could be in the form of a trill - physically demanding structures. Two types of trill has been found in tree pipit, Anthus trivialis, "I" and "M" trills. Trill rates significantly differ among males in this species therefore we assume that repetitive syllable production may indicate male quality. Firstly, we tested if both types of trills are used in aggressive context using playback experiments. Only "I" trills were sung by males in response to playback, regardless of the type of trill involved in playback. Moreover, males increased the frequency of the singing of that trill as an immediate response to playback, and also increased the trill rate in comparison with spontaneous songs. In addition males who sung faster "I" trills were able to maintain the territory. We conclude "I" trills may carry information about the signaller's aggressiveness. Surprisingly, production of "M" trills decreased after the simulated territorial intrusion. Secondly, we tested hypotheses that males modify their response according to the intruders' quality therefore we used playbacks containing...
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Individual acoustic monitoring of songbirds - case study on the tree pipit
Pišvejcová, Iveta ; Petrusková, Tereza (advisor) ; Linhart, Pavel (referee)
In field behavioural and ecological studies, it is often necessary to identify specific individuals. In birds, colour rings are often used as individual marks. However, rings might be difficult to observe, especially in small species and dense habitats. Thus recently, individual acoustic monitoring is becoming more commonly used to study of birds. This method is based on the recognition of individuals and often on the difference between temporal and spectral parameters of their vocalizations. However, in passerine species with more complex song these acoustic characteristics may not be reliable. In my thesis I used an alternative approach for the individual acoustic monitoring, based on differences in syllable repertoires of individual Tree Pipit males (Anthus trivialis). So far I have not found any study that would use a similar approach with other migratory passerine species with more complex song. The main aim of my study was to test the possibility of using syllable repertoires for recognition of specific individuals and to determine if this method is more efficient than identification by colour banding. From four years of research on the Tree Pipits population in the selected location in Brdy I received acoustic data from 59 males that I subsequently analyzed in a bioacoustic program. The...
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Ecology and behaviour of two European pipit species
Petrusková, Tereza ; Fuchs, Roman (advisor) ; Procházka, Petr (referee) ; Matyjasiak, Piotr (referee)
Brief overview of the thesis The thesis consists of íntroductionand five chapters (four published articles and one unpublished manuscript), which deal with two topics unified by the studied species. The first part of the thesis focuses on mechanisms allowing coexistence of tree and meadow pipits, and on the territorial and aggressive behaviour of meadow pipit males. The second part of the thesis analyzes tree pipit song and singing behaviour. Short introduction to the first part presentsbríefbackground on mechanisms allowing coexistence of closely related territorial bird species, and first two chapters focus on local co- occunence of ecologically and morphologically very similar congeneric species: the tree pipit (Anthus trivialis) and the meadow pipít(A. praten'sis).First, we evaluate habitat preferences of these species in syntopy and on two allopatric localities, and show that both species select different habitats in coexistence. ln the next chapter,we test by playback experiments for the presence ofinterspecific territoriality, and conclude that habitat preferences,and not interspecific aggression, are important for territorial selection of the two studied species. In addition, we demonstratethat overexcitation by conspecific song is a factor strongiy influencing behaviour of testedanimals, and...
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The role of the face and the body size in predators' recognition by untrained birds
Fišer, Ondřej ; Fuchs, Roman (advisor) ; Petrusková, Tereza (referee)
The face plays an extremely important role in human communication. It enables individual recognition and provides other information about the person, such as social or emotional information. Human psychology has shown that face recognition uses a specific cognitive process called holistic processing. In recent decades, it has been shown to play an important role in animal communication as well. In the first part of my thesis, I tested whether changing the uniform configuration of a bird's face would affect the ability of the red-backed shrike (Lanius collurio) to recognize a potential predator. Due to unfavourable conditions in both breeding seasons when the experiments were conducted, no firm conclusions can be drawn from the results. They only suggest that the shrike perceives the configuration changes. An essential characteristic of all predators is their size, which affects the ability of prey to defend themselves. Several studies have already found that birds discriminate between different predators of different sizes. In the second part of my thesis, I evaluated experiments in which shrikes were exposed to dummies of two predator species with modified size. The shrikes responded with less aggression to the enlarged jays, whereas aggression increased only slightly to the shrunken crows. Thus,...
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Effect of a dummy on behaviour of Yellowhammer and Chiffchaff males in playback experiments
Kubátová, Hana ; Petrusková, Tereza (advisor) ; Veselý, Petr (referee)
A playback experiment in which a recording of vocalization is played to the tested subject and its response is observed, is a widely used tool for examining bird song and its functions. Most often only acoustic stimulus is used, but sometimes a visual stimulus is also provided in the form of a dummy. Taxidermic mounts or models made from different materials are used as the dummy. It is discussed among researchers, whether it is or is not necessary to use a dummy in experiments and how does its presence affect behavior of the tested individuals. However, only few studies directly focus on this issue and test the effect of dummies. The best way to test the effects of a dummy on passerines in playback experiments is to test the same individuals in both situations (with a dummy and without a dummy) and compare the reactions. The aim of this theses was to perform such experiments on Chiffchaff (Phylloscopus collybita) and Yellowhammer (Emberiza citrinella) males and to find out whether they would behave similarly in both variants of the experiment, or if their reaction would be enhanced in the presence of a dummy. Chiffchaffs reacted significantly more aggressively in the dummy experiment. The biggest difference was time spent by attacking the dummy and staying close to it. In Yellowhammers, the dummy...
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