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Sex and age differences in migration in Anatidae
Prokešová, Erika ; Musil, Petr (advisor) ; Klvaňa, Petr (referee)
The thesis is aimed at intraspecific differences in migratory birds of the order Anseriformes, family Anatidae. It is especially focused on the differences affected by sex and age too. Most of the Anatidae forms its pair-bonds early, not on the breeding grounds like other bird orders do, but on the wintering grounds already. However, it was observed that in some species both sexes don't migrate to the same wintering grounds. Moreover, there are geographical differences between each population really big, so it's not easy to investigate this phenomenon. The adult sex ratio is male-skewed because of their greater survival rate resulting in greater selection by females, especially in species which form their pair-bonds in the end of the winter season. This thesis summarizes the factors responsible for migratory differences during the non-breeding season, then compares conclusions of the studies conducted in this issue between individual subfamilies and tribes of the Anatidae. Key words: sex-dependent migration differences, age-dependent migration differences, early pair formation, Anserinae, Anatinae, dabbling ducks, diving ducks.
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Sex and age differences in migration in Anatidae
Prokešová, Erika ; Musil, Petr (advisor) ; Klvaňa, Petr (referee)
The thesis is aimed at intraspecific differences in migratory birds of the order Anseriformes, family Anatidae. It is especially focused on the differences affected by sex and age too. Most of the Anatidae forms its pair-bonds early, not on the breeding grounds like other bird orders do, but on the wintering grounds already. However, it was observed that in some species both sexes don't migrate to the same wintering grounds. Moreover, there are geographical differences between each population really big, so it's not easy to investigate this phenomenon. The adult sex ratio is male-skewed because of their greater survival rate resulting in greater selection by females, especially in species which form their pair-bonds in the end of the winter season. This thesis summarizes the factors responsible for migratory differences during the non-breeding season, then compares conclusions of the studies conducted in this issue between individual subfamilies and tribes of the Anatidae. Key words: sex-dependent migration differences, age-dependent migration differences, early pair formation, Anserinae, Anatinae, dabbling ducks, diving ducks.
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