Invasion of Sus scrofa into Nozaki Island, Goto Islands, Nagasaki Prefecture, and the following range expansion on the island

Abstract

We report a new sighting record of Sus scrofa on Nozaki Island, Goto Islands, Nagasaki Prefecture, and the following rapid expansion on the Island. The first individual was visually recorded in the deer survey of 2010. On following deer survey of 2011, 2012 and 2014, the number of sighting points and food remains gradually increased and expanded to cover the whole island. In the latest survey, a total of 19 encounters of wild boars were recorded during three days in December 2014. The rapid increase of the wild boar population on Nozaki Island may have been caused by repeated reproduction on the island because subadults were confirmed over several years. In the near future, the number of wild boars on the Goto Islands will increase by reproduction and movement among islands over the sea.