ATLANTA, Ga – Zoo Atlanta’s Lun Lun the giant panda is once again the mother of twin girls.

The zoo announced on Tuesday that DNA testing confirms that the giant panda twins, born on Sept. 3, 2016, are both female.

“What we’re most excited about is that we have two healthy, thriving giant panda twins who have almost reached the two-month mark,” said Zoo president and CEO Raymond B. King. “Our giant panda care team and Lun Lun have done a terrific job helping the cubs reach this point,”

The twins, now nearly 2 months old and each weighing more than 4 pounds, are the second pair of surviving giant panda cubs born in the U.S. and are the second instance of twin girls for 19-year-old Lun Lun.

The tests were done by scientists at the Center for Conservation Genomics at the Smithsonian Conservation Biology Institute.

Both are now covered with a coat of the species’ characteristic black-and-white fur and have begun opening their eyes and ears. They have not yet begun walking.

The pair is expected to make their debut at the Zoo in December 2016 or January 2017. In accordance with the Chinese 100 Day tradition, the twins will be named on their 100th day on December 12, 2016.

PHOTOS: Zoo Atlanta's panda twins