Increase and decline in the density index of Japanese sika deer (Cervus nippon) over 18 years in an evergreen broad-leaved forest with no hunting pressure in the Natural World Heritage Area of Yakushima, Japan.
Japanese Journal of Conservation Ecology. April 20, 2021. DOI: 10.18960/hozen.1923.
The Yakushima sika deer (yakushika: Cervus nippon yakushimae), a subspecies of the Japanese sika deer (Cervus nippon), evolved without natural predators on the island of Yakushima, in Kagoshima Prefecture, Japan. It inhabits the forests on the island which were declared a World Heritage Site in 1993. Within the site, the yakushika has not been hunted in the past 50 years; however, since 2014, their population has been decreasing. This phenomenon is especially curious, as Japanese researchers believed that sika deer populations in Japan would not decrease without human intervention.