The Yaku deer, also known as Nihon shika, is a subspecies of the Sika deer found primarily on Yakushima Island in Japan. These deer are medium-sized, with males typically weighing between 50 to 100 pounds. They have a distinctive coat that changes color with the seasons, featuring spots that help them blend into their forest habitat. Yaku deer are herbivorous, primarily feeding on leaves, grasses, and fruits. They play a crucial role in their ecosystem by helping to disperse seeds and maintain plant diversity. Due to habitat loss and hunting, their population is monitored to ensure their conservation.