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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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Spatial activity of birds and methods of its continuous monitoring
Havelka, Jan ; Sedláček, Ondřej (advisor) ; Kauzál, Ondřej (referee)
The aim of this work was to collect current knowledge of avian spatial aktivity focusing to its internal structure, using modern telemetry devices which allows continuous monitoring of small animal species. In the light of these new methods, avian home ranges seem to be more dynamic structures, changing during diurnal and nocturnal acitvities, breeding cycle, age, sex and social statut of a bird. Thanks to detailed radiotelemetry we can observe even secretive animal behaviour and its characteristics in three dimensions. Continual monitoring allows us to study migration in a detailed way, its influence to other parts of their annual cycle and to asses migration connectivity. In future these new information should be used for targeted conservation of endangered species.
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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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