BEIJING - Tai Shan, the male panda who was born in the United States, has rarely been in the media spotlight for the past year but things are heating for the giant furball as he prepares to build up his fitness in preparation for mating season next year.

"Tai Shan is able to stand with its hind legs as long as three minutes now, which is the minimum time for panda's mating," said Yang Haidi, Tai Shan's keeper from the China Conservation and Research Center for Giant Panda in Ya'an, Southwest China's Sichuan province.

Yang became Tai Shan's keeper in January and began training sessions immediately.

"Last year, the former feeder kept the food in a higher position, which made Tai Shan stand up when he wanted to eat," Yang said. "Now I have to hold up the food for a longer time, which makes Tai Shan to have a pair of even stronger hind legs as the support of its huge body to finish the natural mating by itself."

The 6-year-old male panda is 110 kg, 20 kg heavier than the time it arrived a year and a half ago.

Most giant pandas in captivity lack the strength to hold their large body for mating. But experts from the panda conservation and research center expect to improve Tai Shan's chances of successfully mating.

"A natural way of mating can produce the best little baby pandas, and it is also good for their returning to the natural environment eventually," Yang said.

The center plans to arrange meetings between Tai Shan and several female pandas next year.

"Next year, we will create some opportunities for Tai Shan to live with female pandas," said Huang Zhi, director of animal management at the center. "Hopefully, it can become a father then."

To enhance Tai Shan's physique, workers in the center recently rebuilt exercise facilities to improve Tai Shan's health while it walks in its front yard.

It is currently living in the "Return Pandas' Paradise", which is built only for pandas that were born or have lived overseas before they were sent back to China. Each panda has a house and a yard.

"Adult giant pandas are aggressive, so it's better to keep them separate," Huang said. "When the keepers come to clean their houses, pandas are moved into the cages next to each other, and they can communicate to each other."

The 4-year-old female panda Zhen Zhen and 5-year-old female Su Lin, who returned from the US last year, were living close to Tai Shan in the enclosement. Fu Long, another male panda that was raised in Europe, is Tai Shan's neighbor.

Tai Shan just celebrated his sixth birthday on July 9, his second birthday in China after the panda moved back from Washington DC in early February of last year.

About 60 panda fans came to celebrated Tai Shan's second birthday in China, including many from the US. They said that they were pleased to see a stronger Tai Shan living a happy life in China, Yang said.