WASHINGTON, Aug. 21 (Xinhua) -- Giant panda cub Xiao Qi Ji celebrated his second birthday at the Smithsonian's National Zoo in Washington, D.C. on Sunday.

The outside area of the renowned giant panda habitat was packed with visitors, who came to wish Xiao Qi Ji a happy birthday in the morning.

Keepers made a cake with frozen diluted apple and pineapple juices for the cute cub, and decorated it with a red "2" as well as the cub's favorite treats -- sweet potato, apple, carrot, pear, sugar cane, banana, and bamboo.

Xiao Qi Ji walked to the cake and began breaking and devouring it with joyful fans and visitors spontaneously singing together the birthday song for him and filming the moment.

Mei Xiang, Xiao Qi Ji's mother, turned 24 years old last month and Tian Tian, the cub's biological father, will mark his 25th birthday later this week.

Giant pandas have been living in the Smithsonian's National Zoo since 1972. Mei Xiang, Tian Tian and Xiao Qi Ji are the three giant pandas currently living in the zoo.

The Smithsonian's National Zoo is celebrating 50 years of "unprecedented achievement in the care, conservation, breeding and study of giant pandas."