Abstract
The habitat of the Rock Ptarmigan Lagopus mutus japonicus is the alpine zone of Central Honshu, Japan. The range of this subspecies is the southernmost in the world and is isolated from other subspecies. This monograph reviews past research and examines the problems being faced by the Ptarmigan in Japan. Twenty years ago there were about 3,000 Ptarmigan in Japan. It was suggested that extinction of the Ptarmigan in Japan will arise because the Japanese mountains are isolated from its core range. The characteristic of the alpine zone in Japan is the existence of the Dwarf Siberian Pine Pinus pumila. It was suggested that the existence of the pine is important to the Ptarmigan as it provides shelter and nesting sites. The food habits of the Ptarmigan were reviewed and it was suggested that analysis of dietary differences among regions and quantitative research is necessary. The life history of the Ptarmigan in the alpine zone was reviewed. Seasonal change in body-weight was discussed in relation to their life cycle. The differentiation of L. m. japonicus after the last glacial period, and its genetic diversity, based on haplotype analysis of mt DNA, were discussed. Some problems that the Ptarmigan is confronting now were discussed: decreased numbers in some mountains; invasion of their alpine zone range by Sika Deer and Japanese Macaques; a recent increase in predators, and global warming. The effect of global warming was estimated based on the vertical distribution of territories, suggesting that the number of Ptarmigan will decrease by up to 20.4% when the annual-average-temperature increased by 3°C and the Ptarmigan will become extinct from most mountains currently in its Japanese range. Before its extinction a conservation strategy is necessary and captive breeding skills should be developed.
