tootoo52

Ski Coats The habitat of the okojo ermine, a small species of carnivore that survived the last ice age, appears to be changing as a result of global warming, threatening the species' survival, researchers say.The color of the ermine's coat changes in spring and autumn, in line with the changing temperature of the seasons. However, in recent years its summer coat has been appearing much earlier, while the winter coat has been appearing much later.Many experts believe global warming is responsible, and that the changes to the species' habitat threaten its survival.One such expert is researcher Hiroshi Yashiki, who, with backing from the Environment Ministry, has been conducting ecological research in Shiga Highland, Nagano Prefecture, for 30 years.Yashiki says that on March 30 he found ermine tracks in the snow on a mountain in an area near a ski resort that is 1,600 meters above sea level."In the 1980s, this species was spotted in areas about 1,300 meters above sea level," he said. "But these days, you can't find them anywhere below 1,500 meters."During this reporter's nine-day stay in the area with Yashiki, we did not spot a single okojo.Listed as a "near threatened" species on the Environment Ministry's Red List, the okojo is about 20 centimeters long from the head to the base of its tail and is found in Europe, Asia and North America. In Japan, there are two species of ermine--hondo-okojo (Mustela erminea nippon) and ezo-okojo (Mustela erminea orientalis).Ermine have brown coats in summer and white coats in winter. The coat is believed to change to act as camouflage, allowing them to be better able to hunt for mice.According to Yashiki, in the 1980s, ermine typically had their summer coat by around April 20-May 20. However, during and since the 1990s, the okojo's coat has been changing much earlier, and many have grown their summer coat by late March.Similar changes have occurred with the change to the winter coat. In the 1980s, the okojo would typically have a winter coat by around Nov. 20. But from the 1990s, the winter coat has not been appearing until Nov. 30-Dec. 20.According to Shinshu University's Institute of Nature Education in Shiga Heights, the average high air temperature in March and April rose by 2.1 C from the 1985-87 to the 2003-05 period.The average low temperature in March was about the same, though it was about 2.3 C higher for April.Yashiki believes the ermine's habitat has changed as a rival predator, the fox, has expanded its habitat up in the alpine regions in search of large Japanese field mice and Japanese field voles, which used to live at lower altitudes, but have since moved to higher ground.Yashiki says ermine also are threatened in the Hakusan mountain area on the border between Ishikawa and Gifu prefectures. "Once their habitat shrinks they begin to lose their genetic variations, meaning local populations become extinct more easily," he said.Hideyuki Ida of Shinshu University, who specializes in forest ecosystems, also thinks the changes in the species' coat cycle can be explained by global warming."It's just like how green leaves are appearing earlier than ever, and turning red or yellow later than ever," Ida said. "I'm not sure if we can say for sure it [global warming] is affecting the ermine's changing habitat. But I'm certain the ecosystems in Japan's alpine regions have seen some noticeable changes."