WEB seminar: Dr David Wheatcroft, Uppsala University, Sweden
Dr David Wheatcroft, Uppsala University hosted by Karin Kjernsmo
Life Sciences Building Seminar Rooms (G13/G14)
Maintaining species discrimination via learned traits
Differences among species in mating signals and preferences are often essential to maintain reproductive boundaries. In many species, juveniles learn signals and preferences by first imprinting on and then generalizing from the signals of a variety of adult conspecifics. This learning process could easily lead to cross-species learning if juveniles imprint on the wrong models or over-generalize onto other species, thereby weakening species discrimination. We know that mechanisms exist to limit cross-species learning, but we lack a general understanding of what the mechanisms are and why they evolve in natural systems. I'll present completed and ongoing field studies that aim to address these questions using two closely related species of songbirds, the pied (Ficedula hypoleuca) and collared (F. albicollis) flycatchers. First, where pied and collared flycatchers co-occur, naive juveniles discriminate in favor of their own species' songs, suggesting both that song discrimination is genetically determined and that the underlying genes are divergent between species. Second, female pied flycatchers discriminate more strongly in favor of pied flycatcher song in a population where both species co-occur than in a population where pied flycatchers occur alone, suggesting that interactions between the species drive increased song discrimination. Lastly, I'll discuss a recently completed project using geographic variation in nestling song responses to explore the selective drivers of divergence in song discrimination.