A pair of panda cubs popped out at the Atlanta Zoo at 6:21 and 6:23 p.m. Monday, according to the zoo’s website. The duo are the first giant panda (Ailuropoda melanoleuca) twins born in the United States since 1987 and the first pandas born in the nation this year.

Their mother, 15-year-old Lun Lun, will take turns with zoo staff caring for the giant panda cubs one at a time. In the wild, mother pandas often only attend to one panda twin leaving the other to die. The zoo staff hopes that by rotating the twins between the nursery and mom, both babies will receive sufficient attention and survive.

“Twins are an entirely new scenario for Lun Lun, Zoo Atlanta and our animal care teams, who will no doubt be extremely busy over the next few months,” said Raymond B. King, Atlanta zoo president, in a press release.

Lun Lun gave birth twice before at the zoo, so her caretakers believe she will be up to the task of nurturing these two new additions as long as staff helps her with babysitting. The twins’ father, 15-year-old Yang Yang, and older brothers Xi Lan, 4, and Po, 2 will live apart from Lun Lun while she cares for the youngest family members.

NEWS: Twin Giant Pandas Born in China

The twins join a small number of giant pandas that survive on Earth. The International Union for the Conservation of Nature lists the giant panda as endangered. The most recent population study, done from 2000-2002, estimated that only 1,000 to 2,000 pandas survive in the wild. Of those few, many live in fragmented populations of less than 50, which may be at risk of losing genetic diversity although they do not yet show signs of inbreeding problems.

ANALYSIS: Pandas on the Plate in Prehistory

Fossil evidence suggests that pandas once lived as far south as Vietnam and Burma (Myanmar) and as far north as Beijing, China. However, loss of habitat and hunting reduced their homeland to the western mountains of China.

Images: Courtesy of Zoo Atlanta