Ling Ling, the male giant panda at Ueno Zoo in Tokyo, died of chronic heart failure early Wednesday at age 22 years and seven months, equivalent to about 70 human years, the zoo said.

"He was lying on his back as he died, giving the impression that he had lived a full life," Ueno Zoo director Teruyuki Komiya told a news conference. "It was a peaceful death and it did not look like he had suffered."

According to the zoo, Ling Ling was the fifth oldest male among pedigree-registered pandas in the world.