Late Pleistocene-Holocene non-passerine avifauna of Liang Bua (Flores, Indonesia)

Abstract

ABSTRACT Liang Bua, a limestone cave on the Indonesian island of Flores, has a depositional sequence that spans the last 95,000 years and includes well-preserved faunal remains. Birds are well represented throughout the stratigraphic sequence at Liang Bua. Here, we present the results of the first comprehensive study of avian remains retrieved from Sector XI, a 2 m by 2 m archaeological excavation along the east wall of the cave. A total of 579 specimens were identified as avian, with 244 belonging to at least 26 non-passerine taxa in 13 families. The late Pleistocene assemblage (23 taxa) includes the first recorded occurrence of vultures in Wallacea, as well as kingfishers, snipes, plovers, parrots, pigeons, and swiftlets. Together, these taxa suggest that during this time the surrounding environment was floristically diverse and included several habitat types. Two of these taxa, the giant marabou Leptoptilos robustus and the vulture Trigonoceps sp., are extinct. Eight taxa were identified in the Holocene assemblage, and five of these were also present in the late Pleistocene. Imperial pigeons Ducula sp. and the Island Collared Dove Streptopelia cf. bitorquata appear only in the Holocene assemblage. The differences in faunal composition between the late Pleistocene and Holocene assemblages may reflect a change in avifaunal composition due to climatic and environmental changes near the Pleistocene–Holocene transition, possibly amplified by impacts associated with the arrival of modern humans; however, the small Holocene sample prevents a firm conclusion about faunal turnover from being made. ACKNOWLEDGMENTS We express our gratitude to T. Djubiantono, former Director of the National Research and Development Centre for Archaeology (ARKENAS), for permission to study the Liang Bua bird material. We thank Z. Zhang and M. Spitzer for their help in identifying the bird material and discussions on fossil storks, vultures, and (insular) fossil avifaunas. We gratefully acknowledge K. M. Helgen for discussion on the bat fauna of Flores; G. F. Mees for discussions on the extant Flores avifauna; M. Schellekens for providing unpublished observations on the extant birds of Flores; C. Stimpson for insightful discussions on Southeast Asian swiftlets and providing unpublished data on swiftlet bone material; and B. Pobiner for examining possible gnaw and cut marks. We greatly appreciate the insightful comments and suggestions made by two anonymous reviewers. This research was supported by the Netherlands Centre for Biodiversity and a Smithsonian Institution Postdoctoral Fellowship Award to H.J.M.M. Handling editor: Trevor Worthy.