China will release another captive-bred giant panda into the wild in spring, according to a breeding center in Sichuan.
Hua Yan, a two-year-old female, will be the sixth giant panda bred in captivity to be released into the wild after completing a two-year wilderness training program, said Huang Yan, chief engineer of the China Conservation and Research Center for the Giant Panda (CCRCGP).
"This will be the first time we have released a giant panda in spring. This is part of a wider program to introduce more captivity-bred pandas into the wild to diversify the gene pool," said Huang.
Previously, pandas were released in late autumn or early winter, the time when wild young pandas usually leave their mother to live independently.
"The 'panda-going-into-the-wild' project is at a very early stage, and we need to send pandas back to nature at different times to work out the best time for release," said Huang.
"Plus, we believe a female will be more welcomed by wild pandas when they are in heat," he said.
Hua Yan lives in the wilderness training reserve at Tiantai Mountain in Sichuan, along with another three pandas who are being trained. All the candidates are in good shape despite it being the coldest winter in a decade.
China began releasing captive-bred pandas into the wild in 2006 when Xiang Xiang, a five-year-old male, was released in the Wolong National Nature Reserve. However, Xiang Xiang died roughly a year later after fighting with other pandas over food and territory.
In 2012, 2013 and 2014, Tao Tao (male), Zhang Xiang (female) and Xue Xue (female) were released in Liziping reserve. Xue Xue died in November 2014.
The latest release was Hua Jiao, a two-year-old female, in November 2015.
Researchers have been tracking Hua Jiao, Tao Tao and Zhang Xiang with the help of GPS collars, radio positioning tools and DNA. The monitoring data show the animals are doing well.
Giant pandas are one of the world's most endangered species. Fewer than 2,000 pandas live in the wild, mostly in the provinces of Sichuan and Shaanxi. There were 375 giant pandas in captivity at the end of 2013, about 200 of them at the CCRCGP.