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Long term changes of song within individual passerine populations
Žabková, Michaela ; Petrusková, Tereza (advisor) ; Turčoková, Lucia (referee)
Song is a very important means of communication among passerines - it is species- specific, and they use it to communicate with other members of the same species, but also in interspecific recognition. However, the song differs not only between species but also between conspecifics or conspecific populations, both in space and time. In contrast to groups with congenital vocalisation, i.e. all other bird taxa with exception of hummingbirds and parrots, passerines learn their song during the life. In some species, i.e. open-ended learners, song can change throughout the life. Nevertheless, learning is not the only cause of the origin of spatiotemporal variability. This review is about changes in the song of the individuals as well as within the population of various species of passerines. Song variability can be caused by the changing environment in the surrounding area of the observed populations or ongoing social interaction among the individuals. The individual song stability is more common among species, that are closed-ended learners. Within populations song stability is rather rare.
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Variability of specific structures Tree Pipit
Kozlová, Zuzana ; Petrusková, Tereza (advisor) ; Musilová, Zuzana (referee)
Primary function of birdsong is for territorial defense or attraction of females. Birdsong also contains much more other information and can be used to inform males and females about quality of singing bird. It was demonstrated, that for different bird species condition of male correlates with what structures of birdsong are produced. More complex structures are produced by superior males. Females of some species prefer males with ability to produce more complex structures. This work deals with structures of singing of the tree pipit species (Anthus trivialis). These structures are also known as trills. It is assumed, that trills may contain some information about quality of male, which can be evaluated by males and females. Birdsong of tree pipit contains two types of trills - loud and soft. Loud trills are used in aggressive interactions between two males. Soft trills are not used in aggresive context and they differ in consistency - regularity, that can be expressed as tempo of trill. When measuring tempo of trills for every tree pipit male, the tempo is different among males and also correlates with their ability to maintain stable territory over the entire nestling season. Males with faster (more consistent) tempo of trill had stable territory, while males with slower (irregular) tempo of...
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Effect of a dummy on passerine behaviour in playback experiments
Kubátová, Hana ; Petrusková, Tereza (advisor) ; Linhart, Pavel (referee)
Playback experiment is a frequently used method for the scientific research of the bird song and its functions. A recording of vocalization is played in the territory of the tested male, and its responses are observed. Majority of the studies using playback recordings presents only the acoustic stimulus. Sometimes a dummy is also used to provide a visual stimulus. This review focuses on the effects of the dummy on the passerine behavior in the playback experiments. In the first part a comparison is made within the groups of experiments with the same field of interest. The main questions are: how often is a dummy used in these types of experiments, how do designs and results differ depending on its presence/absence and, if possible, how do researchers evaluate its use. Subsequently, I tried to compare experiments with and without dummy within same species, but because of the differences of the experimental designs and the differences in forms of presentation the results, which were often not comparable, it was difficult to make clear conclusions. Next part analyses the few available studies where both trials with and without a dummy were performed on the same individuals. The review shows that the dummy allows tested males to express additional behavioural patterns, which can be noted by the...
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Signaling function of plumage coloration in Yellowhammer males
Kauzál, Ondřej ; Petrusková, Tereza (advisor) ; Šálek, Miroslav (referee)
Sexual selection theory tries to explain evolution of apparently useless traits which mainly developed in males of numerous species. One such trait is also rich and vibrant coloration, typical for many of the bird species. These traits are difficult to be falsified, and therefore they honestly signal quality of the individual. Carotenoid coloration reflects the health condition and melanin coloration the social status, even though this traditional division might not be as strict according to the latest studies. Apart from these ways of maintaining honesty, recent studies are focusing more also on the effect of hormones, mainly two steroids: male sexual hormone - testosterone -, and the "stress" hormone - corticosterone. Both hormones could positively influence male's sexual traits such as ornamental coloration. On the other hand, elevated levels of these hormones possess risk to the organism (higher energetic expenditure, chronic stress), therefore also might potentially become costly. Using photographs of birds in standardized conditions as well as spectrophotometry I analyzed the plumage coloration of males of the Yellowhammer (Emberiza citrinella). Concentrations of testosterone and corticosterone deposited in feathers were analyzed using the LC-MS/MS. Also, for males in breeding season 2015,...
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Female choice based on colouration and song performance in passerines with sexual dichromatism
Kauzál, Ondřej ; Petrusková, Tereza (advisor) ; Svobodová, Jana (referee)
This thesis is about female mate choice and its influence on two most typical phenotype characteristics of sexually dimorphic passerines (Aves, Passeriformes): their colouration and song. This thesis reviews a range of scientific papers focused on this problematic. Results of these papers show that both colouration and song can serve as an honest signal and give information about health, condition and other characteristics of its bearer. Many papers also indicate that females put such male signals into account when choosing a mate. Special emphasis in this thesis is put on papers which dealt both with colouration and song. Although the number of such papers is very low, it is clear that the quite widely accepted opinion that brightly coloured birds do not sing quite melodic songs and vice versa is generally not quite correct. The biggest problem in the study of female mate choice is the lack of papers which dealt with more than one phenotype characteristics.
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Among-population variability in yellowhammer songs: causes and consequences
Bílková, Jana ; Petrusková, Tereza (advisor) ; Reif, Jiří (referee)
The inter-population geographic song variability can be found in many bird species. One of the most interesting types are dialects, characterized by sharp boundaries between populations of individuals sharing the same particular song type. Despite many years of investigation there is no satisfactory answer to the question how these borders persist over the years at nearly same sites. Distinctions between dialects allow recognition of males from different populations and could influence the territorial behaviour. Various habitats, however, degrade the sound differently; it is therefore possible that specific habitats are preferred by individuals with specific dialects. Both social interactions and acoustic properties of the locality could also be only secondary factors and the dialect distribution could be the result of the habitat distribution either in present or in recent past. In this diploma thesis, several hypotheses were tested on the example of Yellowhammer (Emberiza citrinella) - a songbird abundant in open land with simple song and easily recognizable dialects. The thorough data concerning the habitats and dialect distribution were obtained at the dialect borders at two localities in Czech Republic. The reactions of territorial males to both foreign and their own dialects were also...
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Mechanisms enabling individual recognition of passerine birds
Caha, Ondřej ; Petrusková, Tereza (advisor) ; Vokurková, Jana (referee)
Vocalization allows birds to communicate over long distances or in environments, where can be difficult to detect visual signals. Vocalization can be divided into songs and calls. Song may inform a listener of signal about species, sex, male quality, aggressive motivation and also about singer's identity. Recognition of different individuals is very valuable ability that is commonly used during territorial interactions among males. Correct identification of males, that pose different threat, enable to respond adequately to the situation and save energy or to avoid injury in potential conflict. The ability of individual distinguishing based on song was demonstrated by using playback experiments for many passerines, but it was rarely revealed the way of such identification. This review deals with the issue of neighbour-stranger experiments that confirm the ability of passerines to discriminate between neighbours and strangers. Further, it focus on structures or characteristics of birdsong enabling individual recognition of passerines and their possibly use for individual acoustic monitoring.
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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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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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