Lapita colonisation and avian extinctions in Oceania

Birds perform important functions for the maintenance of island ecosystems, and historically have been highly valued as food and for providing materials for the manufacture of items that display power and status. When Lapita migrants first arrived in Oceania they encountered a much more diverse avifauna than exists today. Naïve endemic fauna, having evolved in isolation, were vulnerable to invasive human socioeconomic systems and introduced invasive mammals. Rapid reduction in avian biodiversity in Remote Oceania and likely impacts on ecosystem functionality occurred. While the evidence for bird extinctions and extirpations in Polynesia is well established, it is not the case for Lapita–bird interactions in the Melanesian and western Polynesian region. Here we review the evidence for Lapita bird exploitation and extinctions in the South-West Pacific region of Oceania. We use the incomplete Lapita, immediately Post-Lapita and pre-Neolithic archaeological record in Oceania to critically evaluate the evidence for the causes of avian extinctions, considering bird characteristics, human activities and biased sampling issues. Our data indicate that bird hunting in Oceania originated in the Pleistocene and was extensive throughout the Lapita distribution, resulting in widespread extinctions and extirpations of land and sea birds. This pattern probably represents a conservative estimate, the full extent of prehuman avifauna diversity and early human impacts are likely obscured by limited sampling of archaeological and palaeontological sites.