Spatial distribution of late Holocene bird bones in the Mason Bay dune system, Stewart Island, New Zealand

Abstract

ABSTRACTMany of New Zealand’s coastal sand dune systems contain naturally accumulated deposits of late Holocene bones, providing an important archive of our pre-settlement faunas. However, the accumulation and taphonomic processes that operate in natural dune deposits are poorly understood. Here, I contribute to our understanding of these processes through analysing spatial patterns of bone distribution in an extensive late Holocene dune system at Mason Bay, Stewart Island. The bone assemblage was collected between December 2002 and February 2003, and included 2880 identified bones from at least 28 bird species. These included extinct species (South Island piopio, Turnagra capensis), regionally rare species (e.g. weka, Gallirallus australis and New Zealand falcon, Falco novaeseelandiae) and locally rare species (e.g. South Island kākā, Nestor meridionalis meridionalis). Significant effects of distance to beach, and distance to the edge of woody vegetation, were found for bones of certain bird groups. The results indicate three main sources of bird bones for the Mason Bay dune system assemblage: 1. nesting colonies within the dunes; 2. storm-wrecked seabirds; and 3. birds inhabiting woody vegetation bordering the dunes. Understanding source biases for dune bone deposits will allow more informed interpretations about the composition of the local prehistoric faunal communities.