Photo taken on July 6, 2018 shows giant panda "Yuan Zai" at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" looking at its birthday cake at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" looking at its birthday cake at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" looking at its birthday cake at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)

Photo taken on July 6, 2018 shows giant panda "Yuan Zai" at Taipei Zoo in Taipei, southeast China's Taiwan. July 6 this year marks the fifth birthday of a giant panda nicknamed "Yuan Zai", whose parents are from Chinese mainland. (Xinhua/Xue Yubin)