The Rock Ptarmigan (Lagopus muta japonica) is a high-altitude bird of the grouse family, regarded as a living relic of the Ice Age. In Japan, it inhabits only alpine zones above 2,300 meters within the central mountain region (the Japanese Alps), where dwarf pine and rocky terrain dominate. It is an endemic subspecies, designated as a Special Natural Monument and listed as a threatened species under national protection.
The male displays dark brown plumage and a distinctive red comb during summer, defending its breeding territory with calls and threat displays. From autumn to winter, it molts into pure white plumage, blending seamlessly into the snow-covered landscape. This seasonal change in coloration serves both as camouflage against predators and as an adaptation for thermal regulation in harsh alpine conditions. The bird is also known to burrow into the snow to withstand severe cold.
A symbolic species of Japan’s alpine ecosystem, the Rock Ptarmigan reflects remnants of ancient cold-climate environments. Its persistent presence amid extreme conditions continues to embody the continuity of mountain ecosystems that have endured since prehistoric times, earning it enduring affection and respect among the Japanese people.