The potential contribution of kurī (Polynesian dog) to the ecological impacts of the human settlement of Aotearoa New Zealand

Abstract

The pre-human Aotearoa New Zealand ecosystem was dominated by avian and reptilian species. Prior to first human settlement by East Polynesian colonists, the top predators were two giant raptorial birds. Aside from humans themselves, colonisation also resulted in the introduction of two novel mammalian predators into this naive ecosystem, the kiore (Pacific rat) and kurī (Polynesian dog). While the ecological impacts of kiore are relatively well understood, those of kurī are difficult to assess, and as such kurī have frequently been disregarded as having any meaningful impact on New Zealand’s biodiversity. Here we use the archaeological and palaeoecological record to reassess the potential impacts of kurī on this ecosystem. We argue that far from being confined to villages, kurī could have had a significant widespread but relatively localised impact on New Zealand’s avian, reptilian and marine mammal (seals and sea lions) fauna as a novel predator of medium-sized species. In this way, kurī potentially amplified the already significant impacts of Polynesian colonists and their descendants on New Zealand’s ecosystem, prior to European arrival. As such, kurī should be included in models of human impact in addition to over-hunting, environmental modification and predation by kiore.

Reconstructing colonization dynamics to establish how human activities transformed island biodiversity

“…Although our modelling shows that Māori are likely to have had little ecological impact on the forests west of the Southern Alps, the pervasive impacts of altered fire regimes (G. L. W. Perry et al, 2012) and introduced commensals such as the kiore ( Rattus exulans ) or the kurī ( Canis familiaris ) were significant (Greig & Rawlence, 2021; Wilmshurst et al, 2008). Accordingly, future modelling exercises that investigate biodiversity change following human-colonisation of New Zealand will ideally need to include the likely impacts of commensals and their cascading effects on native, insular biota.…”

“…Our SEPM projections of the arrival and expansion of Māori in New Zealand closely reconciled inferences of demographic change from the archaeological record, and more recent historical observations, revealing the importance of topography, proximity to navigable water bodies, and the geography of climatic conditions and habitats on colonisation dynamics. These validated simulations provide new opportunities to explore more extensively the potential ecological impacts of human colonisation on New Zealand’s native biota and ecosystems in space and time (Greig & Rawlence, 2021; M. S. McGlone & Wilmshurst, 1999; G.…”