Global human impacts or climate change?: explaining the Sooty Shearwater decline at the Minard site, Washington State, USA

Abstract

Sooty Shearwater ( Puffinus griseus) remains decrease throughout the occupation (AD 1000–1600) of the Minard site (45-GH-15) on the southern Washington coast, USA. Given that New Zealand is one of the major breeding locations for this long-distant migrant, the decline at the Minard site may be due to human impacts on a global scale. In particular, the Maori practice of muttonbirding, the killing and preparation of fledgling shearwaters for storage, may have affected the number of summer migrants reaching the Pacific Northwest Coast. A second hypothesis attributes the decline in Sooty Shearwaters at the site to increasing sea surface temperatures and/or increased frequency of ENSO events during this period. Understanding how Sooty Shearwaters responded to human hunting and/or climate events in the past may be useful for the current management of this species, which has faced dramatic declines in recent decades.