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Migratory divide in European birds
Branišová, Dominika ; Hořák, David (advisor) ; Klvaňa, Petr (referee)
This bachelor thesis deals with migatory divide in European birds, i.e. the contact zone between two population of one species differing in migration path and wintering site. It also comments on related methodological approaches, such as ringing, emlen funnels, satellite tracking or stable isotopes analysis. Between species with best documented migratory divide belong for example blackcap (Sylvia atricapilla) or willow warbler (Phylloscopus trochilus). In birds, many mechanisms are responsible for the creation of the migratory divide: (i) the colonization of Europe after the last glaciation by two or more populations of one species living in refugias, (ii) the presence of natural barrier separating populations and affecting their migration patterns, (iii) the impact of climate change as it causes selection pressure on a certain part of the population and creates differences in migratory behavior. Among key factors responsible for maintaining the divide belong mechanisms ensuring the low gene flow between populations, such as: (i) selection against hybrids or assortative matting. In non-passerines, also other mechanisms have been reported, such as learning migration route in juveniles from adults. Existence of migratory divides is supported by the selection pressure to find an optimal migration strategy,...
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