Panda Panpan eats a birthday cake made of ice and fruit in Chengdu panda base on Sept. 21, 2015. Panpan is the oldest living male panda in the world, his age equivalent to a 100-year-old human. The oldest female is Jiajia from Hong Kong, who celebrated her 37th birthday in July. The average life of the wild giant panda is 15 years. (Photo/CFP)
