The cubs will be rotated between their mother and an incubator to make sure they are being adequately fed and nurtured.

The tiny duo were born approximately two minutes apart on Monday night at the zoo. The cubs—the genders of which have not yet been announced—are the fourth and fifth offspring for 15-year-old Lun Lun and are the first giant panda twins to be born in the U.S. since 1987. (See pictures of zoo pandas.)

While twin giant panda births have been rare in U.S. zoos, they are actually quite common: In the wild and at other zoos around the world, giant panda mothers give birth to twins about 50 percent of the time, explained Zoo Atlanta's curator of mammals,