The taphonomy of big-game hunting in prehistoric New Zealand

Abstract

This thesis examines patterns of bone remains from big-game hunting in New Zealand archaeological sites, and the origins of these patterns from a taphonomic viewpoint. Taphonomy, as a subdiscipline within archaeology, focuses on the events that impact upon bone remains, in the time between an animal's death and the point of analysis, and the effect of these events on the retrieval of information about the past. In spite of the importance of taphonomy to a fuller understanding of bone deposition, there has been relatively little work undertaken in this field in New Zealand, to date.

I examine the effects of two taphonomic agents, weathering (in particular subsurface, as opposed to subaerial weathering) and burning, on moa and seal remains from 17 big-game hunting sites throughout New Zealand. To establish a baseline for understanding the effects of weathering in the temperate climate zone, I conducted a three-year experiment whereby bones were exposed to a range of different weathering situations. The results suggest that subsurface weathering processes begin almost immediately with microorganisms within the soil quickly breaking down the soft tissue. An objective scale was developed for measuring the degree of weathering a bone has undergone, based on the prevalence of markers such as cracking of the diaphysis, the exposure of the underlying cancellous bone and, in the long-term, the large-scale flaking of cortical bone.

The analysis of thesb New Zealand wide archaeological collections provides evidence that, in the sites which I examined, taphonomic agents probably played an insignificant role in determining the fate of bones of big-game species. The taphonomic re-analysis did not alter the interpretation of the prehistory of those sites, and has not altered the interpretation of big-game hunting. The weathering of bone cannot be correlated with soil type, geographic region or with chronological age.

There are two two environmental zones which are exceptions to this. Firstly, areas of the North Island Volcanic Plateau and the West Coast of the South Island, where the high rainfall levels coupled with high soil acidity (pH <4.5) act to breakdown bone at such a rate that it does not survive to be recovered by archaeologists. Secondly, the inland basins of the South Island where pronounced freeze-thaw patterns work to destroy bone remains, which have been deposited in a landscape where soil deposition is negligible and the only protection provided to bones comes from the deposition of silt during the periodic flooding of streams or rivers, within a few decades.