Giant panda Mr. Wu celebrates 4th birthday at San Diego Zoo

SAN DIEGO, Calif. (KABC) -- A panda known as Mr. Wu is 4 years old, and the San Diego Zoo had a little birthday surprise for him.

The staff made an "ice cake" for the giant panda, topping it with apples, yams and four bamboo sticks used to resemble candles. They also filled his exhibit with decorated boxes full of even more treats.

Mr. Wu, whose real name is Xiao Liwu, didn't just have fun gifts, the items were also a way to keep him active and stimulated, according to zoo staff.

He is the sixth panda born at the San Diego Zoo. He was born to mother Bai Yun and is the fifth cub fathered by male Gao Gao.

There are currently three giant pandas - including Mr. Wu - living at the San Diego Zoo. They are on loan from the People's Republic of China so that the zoo may study the endangered species for conservation purposes.

City News Service contributed to this report.