| Summary: | (in English) Interspecific competition is assumed to play an important role in the morphological and ecological differentiation of co-occurring species and could contribute to their speciation. However, empirical studies showing a direct association between competition, ecological niche divergence and specific morphological adaptations are scarce. This thesis focuses on the role of interspecific competition in the differentiation and the evolution of reproductive isolation between two closely related passerine species: the common nightingale (Luscinia megarhynchos) and the thrush nightingale (Luscinia luscinia). Both species are insectivorous and have similar ecological niches. They have diverged 1.8 Mya and their areas currently overlap in a secondary contact zone, where both species still occasionally hybridize. Previous studies have reported an accentuate bill size divergence in sympatric populations compared to allopatric populations, suggesting that interspecific competition might have resulted in feeding niche divergence between the two species in sympatry. Within this PhD thesis, I have studied potential associations between bill morphology divergence, diet composition, habitat use and gut microbiota composition. We found that the two nightingale species have diverged in feeding niche in...
|
|---|
