CHENGDU -- Ten female pandas at a breeding base in Southwestern China's Sichuan province mated since February, a conservation center in the region announced.

According to the China Conservation and Research Center for the Giant Pandas, six of the 10 pandas mated naturally, two by artificial insemination, and the remaining two had both.

The center captive-breeds the world's largest panda population -- 218 as of the end of 2015. Twenty-six female pandas and 19 males have been selected in this year's mating plan.

Pandas have infamously solitary lifestyles -- female pandas only tolerate a male's presence around them two to three days a year during mating season.
Their eggs only live for 36 to 40 hours, making conception even more difficult. The success rate of conception is between 30 percent to 40 percent and no more than 40 percent of cubs survive.

"Male captive pandas capable of natural mating are extremely few -- less than 5 percent of the population. But the pregnancy rate among female pandas receiving natural mating is above 90 percent this year, which is a good sign," said Zhang Guiquan, director of the center.

Artificial breeding of giant pandas in China is planned for the sake of genetic diversity. A total of 56 pandas nationwide have been selected for reproduction this year.