China has introduced six giant pandas into a "semi-wild" environment on Wednesday. This is claimed to be one of the most ambitious attempts so far to build up the endangered population with captive-bred bears.
Celebrities including retired basketball star Yao Ming attended the ceremony in Dujiangyan, Sichuan Province, to mark the relocation of the bears.
Yao Ming said, "I think the most important thing is to keep the balance between humans and nature. We have been talking about it for many years but it is never an easy thing to do. It is the thousand-year-old central thinking in the Chinese Confucian culture."
Chengdu's researchers hope a phased approach will bring greater success. The six giant bears will be set loose for "training" in a controlled rehabilitation area of 20 hectares in Dujiangyan's "Panda Valley" that is still under development.
The animals have been selected according to their health, behaviour and genetic diversity from the 108 pandas at the Chengdu Panda Base.
They are all adolescents - ages two-to-four - a time when scientists hope they will be strong enough to fend for themselves, but still young enough to adapt.
Those who respond well to foraging and other skill training will eventually be released into the nature reserve.
It is hoped that as they mature and breed, they will produce offspring fully accustomed to living in the wild.
Once the 300 million yuan Dujiangyan facility is completed, it is expected to host more than 30 pandas at a time.
The goal is to release 100 animals into the wild over the next 50 years. The researchers involved say patience will be one of the biggest keys.

篮球明星姚明等社会名流和官员参加在四川都江堰举行的放归仪式，首批放归的6只大熊猫将被放到正在建设中的都江堰“熊猫谷”的受控野化区接受“训练”。熊猫研究人员说，有足够的空间进行野外训练，这些大熊猫是根据健康状况、行为表现和遗传多样性，从成都大熊猫基地的108 只大熊猫中选出来的。此次放归被誉为预计将持续50年的熊猫野外放归项目的里程碑。
据称，首批放归的大熊猫属于亚成体，相当于人类少儿期。科学家认为，此时的大熊猫足够强壮，能够保护自己，同时仍有较强的适应能力。在觅食和其他训练中表现最好的大熊猫最终将被放归自然保护区。人们希望，随着这些大熊猫的成熟，它们将繁殖出完全适应野外生活的后代。