A Chinese blue sheep scampers up on the cliff in Ningxia's Helan Mountains on Aug. 30, 2013. Due to their excellent camouflage and the absence of cover in their environment, Chinese blue sheep remain motionless when approached. Once they are noticed, however, they will scamper up to the precipitous cliffs, where they once again freeze and use camouflage to blend into the rock face. (Xinhua/ Peng Zhaozhi) |