Independent introductions of hedgehogs to the North and South Island of New Zealand

Abstract

According to the most recent (2005) compendium on the history of the European hedgehog (Erinaceus europaeus) in New Zealand, this small insectivorous mammal was first brought from Europe to the South Island in the 19th century. This introduction has been presumed to be the source of hedgehogs that subsequently spread to the North Island. This view was informed by the absence of hedgehogs in the North Island throughout the 19th century and no evidence of direct shipments of hedgehogs from overseas to the North Island. Molecular data have challenged this view and suggested that not only was the North Island colonised independently from overseas, but hedgehogs also first became established in the North rather than in the South Island. If true, this finding indicates that the historical record collected by previous researchers might be incomplete. In the present study, based primarily on newspaper articles, we fill this gap by documenting four pre-1900 shipments of hedgehogs to the North Island, thereby confirming the independent colonisation of the North Island. However, we also report on several relocations from established populations in Canterbury (South Island) to regions on the North Island, and none in the opposite direction. We illustrate the importance of linking observational and molecular data with historical records when interpreting the introduction pathways of introduced species.