THE INFLUENCE OF PLEISTOCENE CLIMATE CHANGE ON PATTERNS OF GENE FLOW IN THE AVIFAUNA OF WALLACEA

Abstract

The Pleistocene epoch was characterized by multiple glaciation events, during which global sea levels fluctuated drastically. In Wallacea, this caused the repeated appearance and disappearance of land bridges, subjecting biotic populations to repeated cycles of contact and isolation. In this thesis, I investigate cryptic avian biodiversity in Wallacea and explore how climate-driven changes in land extent affected patterns of divergence in Wallacean avifauna. I describe a new species of leaf warbler (genus Seicercus) and a new subspecies of snake eagle (Circaetus gallicus) from the Lesser Sundas islands. I explore patterns of divergence in white-faced cuckoo-doves (Turacoena manadensis), rusty-bellied fantails (Rhipidura teysmanni), mountain leaftoilers (Phyllergates cucullatus), and leaf warblers (ISeicercus sp.) from Sulawesi and its surrounding islands. I uncover complex patterns of divergence, and discover that the life histories and behaviour of individual taxa most strongly affect the efficacy of Pleistocene land bridges as conduits of gene flow.