publication croisée depuis : https://lemmy.ca/post/38596352

Source: https://www.nwf.org/Home/Magazines/National-Wildlife/2022/Dec-Jan/Animals/News-of-the-Wild

How pikas weather the winter

Plateau pikas (above) spend their entire lives in high-altitude, treeless terrain across parts of Asia where few other mammals ever venture. In a 13-year study on China’s Qinghai–Tibetan plateau—known as “the roof of the world”—biologists with the Chinese Academy of Sciences investigated how these small cousins of rabbits can survive without hibernating in habitats where winter temperatures often plummet to minus 20 degrees F. Using special devices that measure internal body temperature, the researchers checked daily energy expenditures for 156 wild pikas during summer and winter. They discovered that the animals reduce their metabolisms by about 30 percent during the cold months, in part by lowering their body temperatures several degrees overnight. Writing in the Proceedings of the National Academy of Sciences, the team reports that the animals also rely on an abundant—and unexpected—food source: the feces of domestic yaks. “It massively reduces the amount of time pikas need to spend out on the surface,” says co-author John Speakman, an ecophysiologist at Scotland’s University of Aberdeen who participated in the project. Pikas are more abundant, the scientists note, in parts of the plateau where the long-haired yaks also are more prevalent.