Zbarvení zpívajících strnadů

Anotace:

Male colouration and vocalisation are two signals with important functions in sexual selection in birds, both for attraction of females and repelling of male competitors. Brightly coloured males of species with colouration based on carotenoids (which are also used in the immune system) are thought to be healthier, and thus may be perceived as more attractive for female conspecifics and stronger competitors for males. Actively singing males in species with a prominent vocalization are presumably perceived in the same manner. Surprisingly, only few studies have focused on the relation between plumage colouration and song performance within a species. Our model species, the Yellowhammer, has a prominent simple song and distinct carotenoid-based colouration, highly variable among individuals. We will test the hypothesis that colouration and song output are interlinked complementary signals of quality in Yellowhammer males, and affect their mating and reproductive success (which will be evaluated by both indirect evidence and direct assessment of brood paternity). We will also evaluate the parasite load of the males, and its relationship to both colouration and song performance. Specifically, we hypothesize that healthy but young males, dull in colouration, may compensate for less bright plumage through higher song output to increase breeding success.

Řešitelka:

Sharina Jarmila Van Boheemen