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Effect of breeding fidelity on reproductive sukccess of diving ducks
Kejzlarová, Tereza ; Musil, Petr (advisor) ; Hořák, David (referee)
Breeding site fidelity and its effect on reproductive success was investigated in two diving ducks species, i.e. Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula) in the Trebon region and the surroundings using caught and individually marked females, searching for nests, and monitoring of marked individuals and its broods. In both studied species, the fidelity ratio (apparent survival, MARK software) was around 65 %. Evaluating the influencing factors, impact of previous reproductive success in the phase of rearing ducklings was found to be the only one statistically significant factor. Furthermore, we compared reproductive parameters (i.e clutch size, laying date, reproductive success) in the first and subsequent year of study. The statistically significant relationship was found between the timing of nesting in the first and in any subsequent year in the Tufted Duck . When comparing the reproductive success in relation to hatched or unhatched clutches and reared or not reared ducklings, we do not confirm any significant shift. Successful females were not able to improve or even repeat their reproductive success in the following years, which could result in subsequent lower degree of fidelity. Subsequently, there is a female dispersion and reduction of the reproductive success of...
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Spatial variability in population structure of wintering Ducks
Prokešová, Erika ; Musil, Petr (advisor) ; Hořák, David (referee)
5 Abstract This thesis is aimed at spatial variability of population structure of our four most common and the most numerous species of ducks wintering in the Czech Republic. These analysed species are Mallard (Anas platyrhynchos), Tufted duck (Aythya fuligula), Common Merganser (Mergus merganser) and Northern Goldeneye (Bucephala clangula). The field data were collected by January International Waterbird Census in the Czech Republic between 2004 and 2013. Analysed habitat variables include: type of wetland, altitude, population size, level of urbanisation (size of settlement) and mean January air temperature in the investigated site. There was found no significant effect of type of wetland and local population density on population structure in any of these bird species. The next factor, altitude of sites was confirmed as significant only for Mallards, when increasing altitude decreased proportion of males in the population. Furthermore, effect of urbanization was found also in Mallard, when proportions of males increased with level of urbanization, i.e. in larger cities. Finally, , temperature of sites was confirmed to be significant factor affecting population size in the three analyzed species, i.e. in Mallard, Tufted Duck and Northern Goldeneye. Except Common Merganser, ratio of males grew with...
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Effect of breeding fidelity on reproductive sukccess of diving ducks
Kejzlarová, Tereza ; Musil, Petr (advisor) ; Hořák, David (referee)
Breeding site fidelity and its effect on reproductive success was investigated in two diving ducks species, i.e. Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula) in the Trebon region and the surroundings using caught and individually marked females, searching for nests, and monitoring of marked individuals and its broods. In both studied species, the fidelity ratio (apparent survival, MARK software) was around 65 %. Evaluating the influencing factors, impact of previous reproductive success in the phase of rearing ducklings was found to be the only one statistically significant factor. Furthermore, we compared reproductive parameters (i.e clutch size, laying date, reproductive success) in the first and subsequent year of study. The statistically significant relationship was found between the timing of nesting in the first and in any subsequent year in the Tufted Duck . When comparing the reproductive success in relation to hatched or unhatched clutches and reared or not reared ducklings, we do not confirm any significant shift. Successful females were not able to improve or even repeat their reproductive success in the following years, which could result in subsequent lower degree of fidelity. Subsequently, there is a female dispersion and reduction of the reproductive success of...
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