Geographical and climatological data for pikas in this study

Note: Symbols of variables are as follows: Al = altitude (in m); Lat = latitude; Long = longitude; Tm = mean annual temperature(°C); Tjanu = mean January actual temperature(°C); Tjuly = mean July actual temperature (°C); Ffp = frost-free period (days); Rn = mean annual rainfall (in mm). Climatic data were obtained from local weather bureau. Inner Mongolia Grassland Stationa = Inner Mongolia Grassland Ecosystem Research Station, the Chinese Academy of Sciences; Haibei Stationb = Haibei Research Station of the Alpine Meadow Ecosystem, the Chinese Academy of Sciences. The identification of pika species was performed by sequenceing the mitochondrial cytochrome b gene according to Yu et al [71]. The sequences of the mitochondrial cytochrome b gene in pikas were compared with those in the GenBank database.