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Song divergence of Philippine bulbuls (Pycnonotidae) on islands
Rulfová, Alena ; Policht, Richard (advisor) ; Turčoková, Lucia (referee)
Bulbuls (Pycnonotidae) are a biologically diverse group of songbirds that produce a variety of vocalisations. Their songs are very audible, yet the vocal behaviour of the majority of bulbul species has not been formally described or subject to bioacoustical study. The Philippine bulbul (Ixos philippinus) is a sedentary and endemic species of the Philippine archipelago. This thesis presents the first detailed descriptions of its song. The songs were recorded on five islands locations that covered eight different habitats. Nine song features of these species were compared, in order to understand song variations between different islands. In searching for correlations, habitat types and geographical distances between the islands were also measured. The songs of the species found on five islands were readily split up into three groups based on end frequency, syllable number and song duration. The correlations possibly relate to a late Pleistocene connection between the islands and colonization routes of the species. It was found that song frequency parameters in bulbul species is primarily affected by habitat, whilst the effect of current distances between islands was shown to be weak.
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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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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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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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Song divergence of Philippine bulbuls (Pycnonotidae) on islands
Rulfová, Alena ; Policht, Richard (advisor) ; Turčoková, Lucia (referee)
Bulbuls (Pycnonotidae) are a biologically diverse group of songbirds that produce a variety of vocalisations. Their songs are very audible, yet the vocal behaviour of the majority of bulbul species has not been formally described or subject to bioacoustical study. The Philippine bulbul (Ixos philippinus) is a sedentary and endemic species of the Philippine archipelago. This thesis presents the first detailed descriptions of its song. The songs were recorded on five islands locations that covered eight different habitats. Nine song features of these species were compared, in order to understand song variations between different islands. In searching for correlations, habitat types and geographical distances between the islands were also measured. The songs of the species found on five islands were readily split up into three groups based on end frequency, syllable number and song duration. The correlations possibly relate to a late Pleistocene connection between the islands and colonization routes of the species. It was found that song frequency parameters in bulbul species is primarily affected by habitat, whilst the effect of current distances between islands was shown to be weak.
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