Deer

The Ezo Sika deer is a subspecies of sika deer endemic to the island of Hokkaido, although it is not known whether they originated there or migrated from Honshū, the island mainland of Japan or regions further south. It is believed that they may have crossed the Tsugaru Strait between the two islands. A genetic study has shown that the separation of the Sika population occurred less than half a million years ago. The Hokkaido sika is one of the largest sika species, with mature deer sometimes exceeding 200 kg. They also sport the largest antlers of the sika, with lengths often close to a meter. The indigenous Ainu people of Hokkaido named it “Yuk” and had hunted it for centuries and depended on it as a major food source. On the island of Hokkaido, one of the reasons why the most significant damage is caused by Ezo deer comes from the fact that Ezo wolves, which played a role of “natural” regulator by limiting their proliferation, disappeared 100 years ago. The number of deer, therefore, increased explosively. Their numbers throughout the territory of Hokkaido, whose area is twice that of Switzerland, reached a peak with 770,000 individuals around 2011, and has declined slightly since then, to around 670,000 individuals in 2019.