Pan Pan, world's oldest male panda passes away at 31 in China

The world's oldest male panda, Pan Pan, who was battling cancer, died on Wednesday December 28,2016 in Chinas Sichuan Province at the age of 31

Although his death isn't being considered suspicious, an autopsy is being carried out to find out the cause, according to Xinhua news agency.

"Pan Pan was the equivalent to about 100 human years, but he had been living with cancer and his health had deteriorated in the past three days," Tan Chengbin, a keeper with the Dujiangyan base of the China Conservation and Research Center for Giant Panda said.

"He had lost consciousness," Tan said.

Pan Pan was born in 1985 in the wild in Sichuans Baoxing County, but began his life in captivity when he was just a few months old.

Fondly known as 'Panda Grandpa', he was diagnosed with cancer in June this year and also suffered from common old-age conditions, such as cataracts and poor teeth.

An earlier report said he was in a "nursing home" for elderly pandas and though he was very thin he was keeping in good spirits.

"When the keeper called his name and offered him food, usually steamed corn bread or fresh bamboo leaves, he was able to respond and move out to have dinner," the report said.

Pandas are notoriously difficult to breed, but Pan Pan lived a particularly active life for a panda and fathered many cubs over the past 20 years.

He has more than 130 descendants, accounting for 25 percent of the world's panda population bred in captivity.

The average lifespan of wild pandas is normally 20 years, but those in captivity usually live longer.

Pan Pan, which means "expectation" in Chinese, was also name of the mascot for the 1990 Beijing Asian Games, though the mascot was not modeled on "panda grandpa" but on a 36-year-old female panda Basi, currently the oldest panda in the world.

Giant pandas are one of the worlds most endangered species. Fewer than 2,000 pandas live in the wild, mostly in the provinces of Sichuan and Shaanxi. At the end of 2013 China had 1,864 giant pandas in the wild.

There are also 422 in captivity, Chinas State Forestry Administration said