After a month of quarantine for panda twins Mei Lun and Mei Huan, the siblings made their official debut at Chengdu Research Base of Giant Panda Breeding on Dec. 6. 

The cubs are the first pair of panda twins ever born and raised within U.S. territory. Their mother, Lun Lun, was sent to an Atlanta, Georgia zoo in November 1999, under the giant panda breeding cooperation agreement signed by the zoo and the Chinese Association of Zoological Gardens. Mei Lun and Mei Huan are the fourth litter born to Lun Lun.

According to Chen Yi of the base's Animal Disease Prevention and Control Department, the twins have been in perfect health since their return to China.

“During the quarantine, we expelled parasites and checked their excrement on a regular basis according to protocol. All their indices are within the normal range,” Chen said.

Mei Huan eats bamboo

“The twins are very close to each other. They never fought, even during the month-long quarantine,” said Luo Yunhong, the breeder taking care of the cubs. Luo explained that Mei Lun, the older sister, was a little timid compared to Mei Huan when they first returned, and both pandas would only eat cookies produced in the U.S. Now, the sisters are getting accustomed to a Chinese lifestyle.

“Mei Huan can’t get enough of the locally-produced steamed cornbread and apples. Mei Lun has also started to prefer bamboo over American cookies,” Luo added.

Wu Kongju, an expert at the research base, noted that Mei Huan consumes 600 grams of cornbread and passes over 4.5 kilograms of excrement everyday, which is a normal amount for sub-adult pandas.

“All this proves that the cubs are well-adjusted to their life back home,” Wu pointed out.

The twins will be relocated to the Giant Panda Moon Nursery Room after their debut.