One of two female giant pandas is released on Thursday into a national nature reserve in Dujiangyan, Sichuan province, by the China Conservation and Research Center for the Giant Panda. LI CHUANYOU/FOR CHINA DAILY

Two captive female pandas were released into the wild on Thursday in Chengdu, Sichuan province, as part of China's latest efforts to rejuvenate the threatened species.

The move is significant because it helps enlarge the mammal's wild population where it remains sparse, experts said.

The pair－Qinxin and Xiaohetao－were released at 10:55 am in the Longxi-Hongkou National Nature Reserve in Dujiangyan, a county-level city in Chengdu that has abundant stands of bamboo to provide food to the pair.

Qinxin was born on June 16, 2016, and Xiaohetao was born on July 30, 2016.

The two mammals had been prepared for their release since their birth, according to the China Conservation and Research Center for the Giant Panda.

Efforts were made to avoid unnecessary contact between the pandas and human caretakers, and humans entering the training area were camouflaged with panda costumes and the scent of the animals, the center said.

In late November, experts decided the two giant pandas had acquired relatively strong survival skills for the wild.

Nine captive pandas previously had been released, starting in 2006, and seven of them are still alive.

The first captive panda was released at the Wolong National Nature Reserve, 130 kilometers north of Chengdu. The rest were freed at Liziping Nature Reserve in Ya'an, southwest of Chengdu.

The release on Thursday has kick-started plans to enlarge the wild panda population in the Minshan Mountain range, as the Longxi-Hongkou National Nature Reserve has only 10 wild pandas, said Zhang Hemin, the center's deputy chief.

He said the center is planning a release soon in the Daxiangling Mountain range in Ya'an where the animal's population is also sparse.

According to China's fourth panda census, which was released in 2015, there were only 1,864 wild pandas in the world. The number was 1,596 at the end of 2002.

They are scattered in mountain ranges in Sichuan, Shaanxi and Gansu provinces. Sichuan accounts for more than 80 percent.

Twenty-four of the 33 wild panda groups are in danger of disappearing, the census showed.

Eighteen of the groups have fewer than 10 pandas each, which is a sign of danger.