A zoo in Guangzhou, China announced on Tuesday the birth of a rare set of triplet panda cubs. They are the world’s first known surviving trio.

All three baby pandas are in good health so far. China has devoted major resources to increasing the numbers of pandas. The birth of the triplets shows the country’s artificial breeding program is seeing success.

The zoo held off the announcement of the birth of triplets until it was positive that the cubs would survive. According to the official report, the triplets were only the fourth known to have been born in the world through artificial breeding programs. It does not say how many had survived from such births.

Ju Xiao, the mother who gave birth to the triplets was born on September 28, 2002. She is 12 years old.  She delivered the triplets within four hours on July 29 in Chimelong Safari Park in Guangzhou, capital of south China’s Guangdong Province.

Compared to two weeks ago, the three cubs are much heavier than they were first born. They currently weigh 230 grams, 245 grams and 333 grams respectively.

Zhang Hemin, the director of the China Conservation and Research Center for the Giant Panda said, “Since the artificial breeding program started in China in the 1960s, there have been altogether 400 baby pandas born in 300 deliveries. But only three deliveries were triplets.”

In 1967, when the first set of triplets were born, none survived. In 1999 and 2003, only one survived in each birth.

The three cubs will be sent to the research center in southwest China’s Sichuan Province where their mother was born. The center has bred 238 giant pandas and 209 of them survived since its founding in 1980. Currently, there are about 1,600 giant pandas in the wild, where they are critically endangered due to loss of habitat and low birth rates.

In Huaying County, Sichuan Province, a base for training pandas for eventual release into the wild was completed on August 8, 2014. It is expected to accommodate its first batch of pandas in the near future. The experimental training center covers about 13.3 hectares of woodlands in the Huaying Mountain.

Information compiled from Associated Press.